Guest Appearances

I gave a Keynote at Pocket Gamer Connects in London a while back, based on the 666 post.


And, Pollen.VC did a story on my thoughts on retention:


Making progress

At times, I’m wondering: does it even have to be a game in there?

F2P games can be split into the core and the meta game. The core game is the part that people recognise as a real game. It will have some challenge to it, usually either a mental challenge, like in puzzle games, or a reaction challenge like in action games. The meta game is really about progress – and is some form of “the more you grind (or pay) the further you will get”.

Some of the games I have played the most, did not really even have a real game in there. At times, they are just a progression loop. A progression loop that feels really, really good.

The most obvious example of this is likely AdVenture Capitalist or Cookie Clicker. Try them out, if you have not done so. You buy businesses, they generate money and then you buy more businesses and they generate more money – until you are quickly in ridiculous amounts of money territory.

They simply made you progress along an exponential curve, and that feels really good. You keep on becoming twice as good every time you play. Of course, if you plot that on a log scale, it’s just a regular straight line again – just as the plots you see of Moore’s law.


Last week, I wrote about the loop in Hill Climb Racing, where you upgrade a car, try it out a few times, realise you’re just one game away from having enough money to upgrade again, play that one time, buy the upgrade and you’re back where you started – wanting to try out your new and better toy a few times. It really never ends.

Rovio launched a great build and battle game called Plunder Pirates back in 2014. Shortly theareafter I spoke to Wilhelm Taht (EVP Games @ Rovio) who was also hooked on another pirate game called Pirate Kings. He described the game as “Plunder Pirates with all gameplay removed”. Please note: that was a compliment to the game!

Some of the top grossing games, like Game of War, Mobile Strike and Vikings aren’t terribly far from that in the early parts. I cannot recall making any significant decisions in the first few days of e.g. Mobile Strike. I was simply tapping what they told me to tap and progressing accordingly.


When we dig deeper, some ‘real’ games are not that far removed from this. Plants vs. Zombies is really a great game with some deep strategy involved. However, their learning curve is so gentle that my wife played it through twice (normal and hard mode), and lost a level only once. If you’re anyway going to let the player win, why bother with the gameplay in between..?

The feeling of progression is so strong a motivator that it can apparently stand on its own in some cases. But how do you get enough content to make the progression feel good?

One first and easy solution could be to throw a lot of stuff into the game. I believe that is dangerous, and there’s such a thing as too much choice for people. With too many options, you just end up confusing people. In the real world, there was a famous experiment with jam sales in a supermarket. They set up a tasting booth with a huge variety of jams. Most people who walked by stopped to test some of that huge selection, but very few of them bought anything.

Next they set up a tasting area with only 6 jams. Much fewer people stopped to taste the jam, but of those who stopped, many actually ended up buying. They felt comfortable in their decision that they had made the right choice, and thus ended up spending.

The relevance for making games is that we should make quite few things to select among, but make them ‘deep’.

What I mean by making them deep is have a lot of levels to upgrade it. Don’t offer 3 upgrade levels when you can offer 30. The great thing about depth is that you don’t have to expose the players to all available upgrade levels at the start. You can have a lot of depth without overwhelming the player.


The Rule of 10%

Most upgradeable things need to be upgradeable by 10%. We have designed games where they player gets one unit of some good. Offering an upgrade from 1 unit to 2 units is way too powerful an upgrade, and giving the player 3 of these things would completely break the game. Don’t do that. Make sure you have enough continuous variables that you can let the player upgrade 10% at a time, two dozen times.
You can stretch things further with so called gacha mechanics. That is, don’t sell item X to the players directly. Instead sell them a lottery ticket that gives them any of a bunch of items. They might get X, or they might get Y. If they get Y, they just sell it, collect some more money for another lottery ticket and hope that they get item X this time.


You can, and should, combine these techniques. In Clash Royale, your troops will be about 10% better with each upgrade. But you cannot buy those upgrades directly. Instead you open a chest with random cards. Then you might actually need to find 50 of these cards in order to get your character to the next level. And once you have found 50 of them, you still need to use some gold for the actual upgrade. Which gets you a 10% improvement. And there’s always another 10% improvement after that… Brilliant!
(They do sell you cards directly too, which allows you to bypass some of this randomness – if you spend some real money).
So far: we need a decent, but not too large a variety of things to upgrade, and a very deep upgrade path that we can stretch further with some random and collection mechanics.
With the meta game and progression this important, is that all we should focus our energies on as game developers? I would say no. This one will be fairly controversial, but I will claim that the business has changed, and new things are now important for building successful mobile games.
The core game is what consumers care about. Just ask a player to describe Candy Crush Saga, and they will promptly give a description of Bejeweled, as they share the same core game.
The meta game is more important for the developers, as this sets the pacing of the game, and eventually determines retention and monetization. I.e. the meta game pays our salaries.
In order to build a fresh new game for players, the smart thing to do is, therefore, to be innovative with the core game, while staying fairly safe with the meta game. By staying safe, I really mean adapting proven meta game mechanics to the innovative core game ideas that you have chosen.
This first wave of F2P success of mobile were actually copies of successful core games, with innovation on the meta game. That likely no longer works. It worked back then, because F2P was new on mobile. Someone had to invent a working meta game for F2P on mobile, and it did not matter if you copied the core since the competition was asking for money up front. The first ones with good core games plus working meta games got money making machines where they could spend on advertising and make more money back. That’s no longer the case.
To get to the top now will likely require new ideas for the core game – and building that is likely to be hard and risky even for experienced and great teams. Clash Royale really brings something new to the market, but it took an amazing team quite a few tries to get there.

Can we stretch this Core?

Does our core idea work? Can we build lots of variation without changing the basic User Experience?


Back in the day, when we started planning our Benji Bananas game (some 4 years ago now), we analysed some of the top performing mobile games. A thing many of them had in common back then, was a really slick user interface. We simplified it down to “one touch or one slide”. Think about what you do when playing Angry Birds. It’s really just sliding your finger once over the screen to do one move. The more advanced birds require you to slide once and tap once. It was the same thing with other games of the era: one slide to Cut the Rope or dig the channels in Where’s My Water, one tap to make the Tiny Wings bird dive, or the Jetpack Joyride guy fly.

We took this one touch to heart when doing the design of Benji. Any idea that required something more complicated was immediately thrown out.

Games have become more complicated since then – likely because people are now more familiar with touch screens, and with games on them. The players are not overwhelmed as easily anymore, which gives us a bit more freedom to work with, but not much. Once you have settled on the core user interface – what you do to make one ‘move’ in the game – you need a really, really good reason to introduce something that requires the player to interact in another way.

The question then is: how do we build a game that will last at least 6 months while always sticking to this one simple gesture for the UI? Mobile games have two hard requirements that are in conflict with each other: simplicity to get players, and depth to keep them. It takes a really skilled team to bridge this conflict.

Another similar requirement is to make the game last for 6 months without needing artists, writers and programmers to manually create content at light speed. The question is: can we stretch this simple core game into a full mobile game with great long-term retention?

One great way is to build features into the game that can be combined with each other. You only build m+n+o features, while the player gets to play m*n*o combinations.

Let’s take Hill Climb Racing as an example. It’s a good example because it’s so simple, there’s not a huge amount of stuff to look through. At the start, they had a few cars, and a few levels in which to drive the cars (by now they have some 20 each). If I have unlocked 5 cars and 5 levels, there are 5*5= 25 different versions of the game that I can play. Unlocking a sixth car will add another 5 combinations: I will want to try out the new car I just got in all the 5 levels that I have unlocked. By the time I have tried it in all of them, I have earned enough soft currency to upgrade the engine a bit.

Now, of course, I want to try out how well that newly upgraded car behaves in all 5 levels, after which I have enough money for new tires… You can see how it goes. After a while I think this new car would be great in that new level. I unlock the level, and want to try out all my 6 cars in it. 36 games later, I’m this close to earning yet another upgrade or unlock.

The more you can make your features interact in such a way, the more efficiently you will be able to build a long lasting and interesting game without having a huge team working on it.

Another big feature is to make the game player vs. player (PVP). Most forms of PvP can be seen as variants of user generated content. When I’m building my Clash of Clans village, I’m really creating a puzzle for someone with an army to solve. Even if I’m just playing Chess against someone, I’m offering them the same challenge as a level designed by the game company otherwise would. Multiplayer games have been a trend recently, and is likely to continue for some time to come.

Multi-player is also great for triggering competitiveness among your players, and thus it is great for retention.

One great way to get players emotionally attached to your game is to let them build permanent things in it. That’s why different sorts of town building games are so popular. At times it feels like the town building aspects were just glued on to something else, but it still seems to work. For instance, the Facebook game Gardens of Time gave me that feeling:

Building permanent stuff and upgrading them leads me to one particular mechanic that I must confess I did not get for quite some time. Clash of Clans had the concept of builders. You could get several of them, and use them to upgrade several things in parallel. I loved it, and spent my hard currency mainly on them. Later games have, however, gotten rid of the concept with multiple builders. They are not in Boom Beach, nor in Game of War or Plarium’s Vikings. Why not?

The thing is that multiple builders will waste the content the developer made for the game by letting players do several things at once. As a player, I am no more likely to return to the game if there are two finished buildings waiting for me, than if there is only one. And if one is enough, offering two, three or four is a waste. Letting players get through your content at twice or three times the speed is a bad idea. Hence, new games usually have just one builder.

These are some of the best ways to make your development budget stretch out to hundreds of hours of gameplay. Next week, I’ll dive into the importance of progress, and how to create that feeling in players and after that it’s going to be about why Match-3 is such a great core for a mobile free-to-play game.

Paid User Acquisitions

This week let’s go into what you can do to get users with money: paid user acquisition. Again, this is the broad overview of what is useful to know for an indie developer just transitioning into paid UA, not an in-depth article on the details.

First, let’s get the simple and modest PR message out of the way. You probably should do one, but don’t expect much from it unless you are one of the top games companies around and people have been waiting for news about what you’re about to do next. Supercell’s announcement of finally launching Clash Royale as their fourth game – after years of simply slaughtering games that were good, but not insanely great – will be considered global news.


For the rest of us, sending out a PR message is unlikely to move the needle on downloads. It’s sort of the same thing as with fishing for earned media by talking to press, etc.

Another way to gain paid visibility is to ‘bribe’ YouTube content creators to do a video about your game. There are quite a lot of creators who are primarily making videos about games. The biggest YouTube star of them all, PewDiePie, started out by mostly making videos of himself playing games. Of course, these guys will make a video about your game out of pure interest in case they find your game interesting. Otherwise, you can, as I said, pay some of them to do it.

The YouTubers have people who follow their channels. This is the main metric that their agents will quote if you want to buy their services. It does not mean that your video will be watched by that many people. Just that that number of people will be notified about the new video being posted, after which some of them will decide to watch it.

As I said, PewDiePie has the largest number of followers at some 41 million. Some fairly large ones have single-digit millions of followers, and quite a lot of them have hundreds of thousands of followers. A typical PewDiePie video might be watched by some 2 million viewers, while someone with about half a million followers might get 10-50k views per video.

If you are interested in getting downloads, you then need to have a guess at what percentage of video viewers will convert into game downloads. Usually, that’s not a whole lot, honestly – even though being played by PewDiePie was, according to legend, one of the things that fed the Flappy Bird phenomenon. You can watch that video here:

However, if you look at the Top Downloaded chart for Flappy Bird, you’ll see that it had been at number 1 for some weeks already on January the 27th, when that PewDiePie video was posted.


On to some more mainstream ways of acquiring users, then.

I’ve already written a few articles about Ad Networks. They are the usual suspects when it comes to acquiring users, and there’s quite a number of them: Ad Colony, AdMob, Chartboost, Unity Ads, Millennial Media, Supersonic, Facebook, etc. Mainly, they will show your ads in other (free) apps, with a link to your App Store page.

There are several types of ads:

  • Banners similar to what you find on webpages were some of the first ones to move over to mobile. They have largely gone out of fashion by now, as they don’t work for anyone. They annoy the player, don’t work for the advertiser and make no money for the game that shows them. Just skip these.
  • Interstitials are full-screen ads (pictures) that will appear between play sessions. They work a lot better than banners, but not quite as well as the trend now, which is video ads.
  • Video ads are the mainstream marketing tool by now. They are typically about 30 seconds long, and either shown in between play sessions without anyone asking for it, or, preferably, when the user asks to see one in exchange for some in-game benefit – called incentivised video ads.
  • ”native ads” is a hyped term that basically means that the ad network does some work to make the ad fit in with the game’s overall style.


These ad spaces are then sold in a form of auction. That means that you do not typically negotiate much regarding pricing. You simply set what you want to bid, and an automated system takes care of it. The higher you bid, the higher your placement and thus the more visibility you will get.

Different ad sources are likely to vary wildly in the cost you have to pay for a download. CPI, Cost Per Install is the typical way you will compare the cost between different channels, even if what you are not necessarily paying for installs, but might be paying for views (CPM, Cost Per Mille, that is per thousand views). As I wrote in a previous article, the difference in CPI between two ads can easily be a factor of 10. Some installs cost us over $5, while others were under $0.50.

An expensive install will be over $5, while anything below $1 is considered cheap by now. It obviously also depends on the country you are advertising in. Some of the most competitive markets are much more expensive than developing markets. Of course, it does not make much sense to pay for a download in a market where you know that the players will never have money to pay for anything in the game. That is, their Lifetime Value (LTV) is very low.

Another thing that affects the price is the volume you want to buy per day. It is much cheaper (per install) to buy lower volumes. The higher the volume you want to drive per day, the more you have to pay for each install. That auction system basically forces you to bid high to reach volumes.

What your most direct competition is bidding will also affect what you need to bid. If two games are targeting the same potential players, the one who can afford to bid higher will win and crowd out the other one. That’s a very good reason for you not to clone Clash of Clans or Game or War!

To have a look at what other’s are spending, head over to Appscotch.


A lot of companies are targeting the US first. There are two reasons for that. One is that the US is the top revenue generating country (together with Japan and Korea). The other is that trends from the US often spread to other markets, and more seldom the other way around. This is similar to the music industry: while every country has their own charts, Germans will hear about a band that tops the US charts, while Americans will certainly not hear about a band that tops the German charts.

Speaking of charting, that was a very popular strategy early on for the App Store and Google Play. They gave a lot of space to the Top charts, which led a self reinforcing spirals for the most successful apps. Apple and Google have changed the stores since then, and now the self reinforcing spirals are not as strong anymore.


A “burst” campaign is one specifically designed to get the app to rise on the charts, without much care for the quality of customers attracted. The hope is that the app will benefit simply from the exposure it get by being high on the top downloaded chart. The cheapest way to get there is through ‘incentivised’ installs. That is, to bribe a player with some items in one game, in order to get them to install another game. Most people who install through such an offer will hardly ever open the target app, and their retention in that app is dismal. They are cheap though, and can cost from a few tens of cents to about $1.50. As with all other ad prices, they are cheapest in Q1 and most expensive during the Q4 holidays.

This way of gaming the App Store and Google Play is not really popular with the platform holders. They have therefore limited its appeal by giving less visibility to the top charts, by calculating the top charts based on more than simple downloads (counting retention, ratings, etc. on Google Play), and by outright banning incentivised installs (App Store). If you still want to use the burst strategy, it’s best to concentrate your firepower to select markets and likely either iOS or Android. With incentivised installs, you only benefit if you get into the top 10. Otherwise you are wasting your money.

The retention and monetisation of players will be different depending on where they come from. Roughly speaking, the more they know about your game before downloading, the more probable it is that they will actually enjoy it and stick around. People who have seen a video with gameplay explained will be very likely to actually show good retention. People who download a game their friend showed them will also stay. The downloads you get from getting featured are slightly worse, while banner ads and especially incentivised downloads can be really bad.

Since this is quite complicated, with varying cost levels together with varying value for the customers acquired, there are several companies that specialise in it so that you can outsource the trouble. It will typically cost you around 10% of your ad budget. The quality you get really then depends on how important your business is to them, and how much attention you will therefore get from the “ad ops” – the guys who are running the optimisation.

Speaking of budgets, when you do low volume paid UA, you are likely to just buy it with your credit card through an automated system. That will become a problem very quickly once your volumes go up. Most credit cards have their credit limits at some thousands of euros/dollars/pounds, and the UA budgets quickly rise above that. You will have to ask for credit with the ad networks to get around that.

One interesting way to stretch your budget is provided by a company called Buying ads at even moderate scale will quickly tie up a lot of money. Say you’re buying installs for $10k per day, and you’re so incredibly lucky that they players immediately spend an equal amount in the game – that is, everyone customer you acquire is immediately profitable. Apple and Google will pay you with a small delay, and that delay still needs to be financed. At $10k per month, you need about half a million to buy ads before you start getting your money back from Apple and Google (45-60 day delay at $10k per day). looks at your accounts on the App Store and Google Play, and then lends you the money the next day – a handy tool when scaling up a game company.


Last, if you want to become an expert in this field, you should follow blogs such as Eric’s at, and attend conferences such as The Business of Apps.


Free User Acquisitions

I’ve noticed a pattern when talking to indie game developers who have been successful. A lot of them are not only really good at making games, but also at acquiring users.

This post will be an overview of everything user acquisition (UA) related. Obviously, I cannot cover everything in very great detail, and I encourage you to head over to the real experts for the in-depth stuff. For instance, Eric’s blog at is a really great resource.

First off, let’s do the rough divide between what you can get for free versus what you have to pay for.

Let’s start with the free stuff and continue with paid UA next week.

If you already have some popular apps, you can cross promote your new game from them. Some 5 years ago, this was mainly what publishers were offering game developers. They wouldn’t say it directly, but their offer was really “we’ll talk to Apple and hope they feature your game, and we’ll cross promote from our other games for a week”.

Cross promotion is, of course, dependent on how large an audience you have to cross promote to. That is, what is the Daily Active Users (DAU) number of your existing apps. You should expect a certain percentage of those people to download your app. As an example, let’s use our Benji Bananas game, and our friends at Fingersoft.

Fingersoft got started by building a few novelty camera apps with funny filters – back in the days when such things as a cartoonish filter on a smartphone camera were considered funny novelties. They then used their camera app users to cross promote the launch of their first game – Hill Climb Racing. The downloads they got that way – only some thousands during the first day – were enough to get the game on Android’s Top New Games list. That got some people to notice, which led to more downloads, which led to a higher chart position and more downloads in a self reinforcing cycle.


Cross promotion (and other tools that can get you a short burst of installs) is really a way to prime the pump. A good game, with some virality, can start to spread if it’s given a chance. You just need to get over the critical mass first. What the critical mass is will depend on the game. Some thousands was enough for Hill Climb Racing, 75 000 was clearly enough for our Benji Bananas game, and 40 000 was enough for Draw Something.

When we partnered with Fingersoft they used Hill Climb Racing to cross promote our Benji Bananas game. The first day we got some 75 000 downloads, which put us pretty high on the charts already. From then on, the game started growing more based on chart positions than on cross promotions. You see, a good game will have a lot of players coming back to it every day. The first day you cross promote, everyone of the Daily Active Users will see the ad for the new game for the first time. The next day, most of them have already seen it, effectively likely to halve your cross promotion power. In our experience, you can get up to 5% of your DAU to install the new app.


A good publisher really will have a better chance of getting Apple and Google to feature you than most new indie developers have on their own. It’s a sort of pre-filtering. As the vast majority of all games that are launched are just not interesting, merely getting picked by a publisher sends the signal that some external party is interested enough to at least commit some resources (even if it might only be their working time, in some cases) to your game. That means that the game is at least worth taking a look at for the featuring teams and possibly for some news sites.

Otherwise, the way to get featuring is to build something different, something with really high production values and generally something that will make Apple’s or Google’s products to look great.

The next thing to look at is optimising your App Store or Google Play page. Getting the right text and keywords there is a form of Search Engine Optimization. The key is to get high rankings on a few keywords that are often used. You probably should not go for the very top keywords, as the competition there is so tough that you will never get high up when people search for things like “free game”. Try to own a word that’s trending, but that others have missed. You should be able to drive some thousands of downloads per day using this strategy.

Here are some further hints and tips from Chartboost on how to optimise your keywords. Optimising the screenshots is another part of the search engine optimisation.

Last, you can try to earn publicity by speaking to various media and trying some “stunts” to get free publicity. Unfortunately, this is very hard to do for mobile games. Jake Sones wrote openly about his marketing efforts that did not lead to much.

Traditional media often do not really take mobile games seriously as content. Stories about mobile games are often more about the business aspects than about what the games are about, as Thomas Bidaux points out on Chartboost’s blog.

It’s pretty much the same thing with YouTubers. There are quite a lot of creators who are primarily making videos about games. The biggest YouTube star of them all, PewDiePie, started out by mostly making videos of himself playing games. Of course, these guys will make a video about your game out of pure interest in case they find your game interesting. However, mostly they find PC games interesting, and a mobile title will have to be something special in order to attract their attention.

What I completely left out of this now, is designing the game for virality. That will have to be its own article. Next week will be the overview on how to acquire users with money.

Using Machine Learning to tune a game

AB-tests are nice and all, but we need to go to the next step.

This is David. He’s a nice Columbian guy that somehow lost his way and ended up in Finland. He designs games for us, looks at data and tunes the games based on this. Here’s a sketch of how it works:



What happens here? First of all, the player plays the game. Each game session is reported back to our servers. Don’t worry, it’s all anonymous. As in player #485712454 failed at level #57, or player #20495 succeeded at level #127. What we use this data for is basically making the game better. We can see which levels are too hard or too easy. If a level is too hard, people will obviously get stuck, and then quit the game. If it is too easy, people get bored, and also quit the game. If the game is balanced just right, people feel challenged and then feel good about themselves and the game when they pass the challenge.

To achieve the balance, David will look at the data on how players progressed in our game. He will then adjust the difficulty of the game by tweaking level data and various variables.

The second part of the server is where the rules of the game are kept. Here sits all level data as well as some globally configurable rules. At every startup, the game client will download a new set of rules and levels from this server. David will simply put his new configuration on this server, wait for players to play this new, tweaked version, and look at the analytics data again.

There is some lore in the game development community on how to build an optimal challenge curve. Please note that what follows are the “best practices” that are not exactly “scientifically proven” (I know, that’s an oxymoron).

The first thought is likely that you make the game increase in difficulty in synch with the players’ improving skill. That might work, but we can do better than that. It is not optimal to always have the player under equal pressure. In fact, that can be exhausting. So, let’s add some waves. Build up to a challenging level, and then when the player finally passes that level, let them rest and feel good about themselves with a few easier levels. Give them some time to breathe and recover from the challenge. Then you build up to the next challenge.

For F2P games, you likely want to increase the difficulty just a tad more every few waves. These tough levels are where you hope that the player will end up paying you. Get them 98% of the way to finish a level, and hope that they pay you for a booster that gets them the last 2%. What we end up with is a curve like this:


It is not only important to look at how often people win or lose, but also how people lose. If they always lose in exactly the same way, they will soon get frustrated and quit. Keep track of how close to winning they are when they lose. And make sure that varies, with a large percent of close calls where the player almost won. Again, that is when they most likely end up paying. When they play the level for the 20th time, and get 98% of the way to winning. Now they know that they can use a booster to get over the edge, or they will likely play another 20 times until they are again this close to winning. What an opportunity! The booster suddenly seems like really good value.

So far, the wisdom of the game development community. But are these guesses, or facts? And how do they apply to your specific game? This is where the machine learning algorithm comes in. Markus here is doing his PhD in Machine Learning at the University of Turku, right next to us. He’s looking at what can be done with the data generated by our games. We could try something like this:


The game reports to our servers, the analytics engine looks at things like fail rates how close to winning they got, who paid for boosters and who stopped or kept playing.

What the machine learning algorithm does is this:

-it has been told to maximise the player long term retention.

-it get’s all the player behaviour data

-it modifies the rules, and looks at how the modifications affected the retention

-it automatically learns from this feedback loop what modifications were good and which ones were bad

It is quite reasonable that the machine learning algorithm will learn the same rules that the game development community have figured out. But that is by no means certain. We might have had it all wrong the whole time since no one has really run a robust enough experiment.

Admittedly, it’s still early days for us in trying this out. I’ll let you know if it works once we get that far.

All About Retention

It’s all about keeping your players. Seriously, nothing is more important!

This week is about how different features of the game will affect how long your players will stay and enjoy your game. It’s a rough sketch based on what we have learned from the dozen or so games that we have made so far.

First some basics (skip the next two paragraphs if you know what retention is):

Retention is the number of players coming back to your game after X days. Say you get 1000 people to download your game on the 31st of January. Those 1000 people are called a “cohort”. If 400 people from that cohort play on 1st of February, then your one-day retention is 40%. People who play on the 2nd of February do not count towards the one-day retention (those would count towards the second-day retention), and people who downloaded on the 30th of January also do not count (those are another cohort).

Obviously, people from this cohort who play on the 7th of February count towards your 7-day retention, and people who play on the 28th of February count towards your 28-day retention. The basic benchmark has been that your 1-day retention should be 40%, your 7-day retention should be 20%, and your 28-day retention 10%. Some people use 30-day retention instead of 28-day, but as retention is also dependent on the day of the week, you will get more stable data if you’re tracking exactly 4 weeks. This is because people have more time for playing games during weekends – which means that someone who downloads on Friday is more likely to play on Saturday than someone who downloads on Sunday is likely to play on Monday. The one-day retention varies by some 5 percentage points around weekends for our games.

For some more nuanced data, here’s a cheat sheet for what Key Performance Indicators (KPI’s) you should be aiming at with a mobile game. This is borrowed from a talk Ben Holmes from Index Ventures gave at Slush. It’s an incredibly useful summary.



According to this, our Benji Bananas game had a “Best in Class” 1-day retention, a good 7-day retention and a Less-than-viable 30-day retention. And, the monetisation? Let’s not talk about it! With some 75 million organic downloads, the CPI is just about 0, though.


This is all very easy to say, but incredibly hard to do in practise. At Tribeflame, we have a philosophy of “soft launching” very, very early. As soon as we can somehow claim that it’s a game, we start testing it. This is different from what most companies call a soft launch. “Pre-Alpha launch” might better describe it. At that point, there is basically just the core of the the core loop. It’s not pretty, and you cannot play it for a long time. It’s also buggy, and players have no way of spending money in the game. The feedback is always that the game has lots of huge issues, but that’s fine at this point. Seeing the game improve and the metrics rise gives us a rough guide to how different features of the game influence retention.

As I already mentioned, we start testing with an ugly core game. With this, we should be able to get a one-day retention at around 20%. At times, we can even be below that, but should quite quickly improve it. There is not yet enough content such as upgrades or levels to keep players in the game. Even 7 day retention is going to be way below 10% at this point. The game might also be confusing, since there is not yet a good tutorial.

Let’s focus on the tutorial next. This will, obviously, help us keep more players as we are not losing people simply because they get confused. Getting the tutorial in order should add to 1-3 day retention clearly. Of course, it does not help that much later on – with the people who already understand how to play the game. However, there are the players who would have stayed for a very long time, had they only at the beginning understood how to play and had a good first impression. I’ll write another article about tutorials and the first session later on.

Another thing that helps early on is high production values. Pretty graphics, nice animations, etc. These things will help you get users more cheaply (lower your Cost Per Install, CPI). There’s a higher chance of featuring when your game looks amazing. People who go to your pages on Google Play or the App Store have a higher chance of downloading your game. And it will help with virality – people are more likely to show their friends pretty things. What it will not do, is help you with long term retention. Someone who has played the game for hundreds of sessions is most likely almost blind to your graphics already. They take the look for granted, and focus on their long-term goals in the game. To help you out here, you need a good meta game.

The meta game is about what happens between the game sessions. What is the player dreaming of achieving in between the daily grind of play sessions? This is what will lift the tail of your retention curve. In short, a good meta game will set the player up with a long term goal – like build the perfect fortress, or assemble the perfect team or deck of cards. This long term goal is then divided into short steps – making the player feel clear progression every step of the way.

Draw up the glorious mountaintop that the player will conquer, make it look like it’s closer than it really is, and then dangle a carrot in front of the player, and celebrate every single step they take on the way. Just one more turn and I will achieve that milestone, then one more to get to that one, etc. etc.

This is, for instance, why there is a huge amount of achievements and missions in many successful F2P games. Just telling people what to do next is one surprisingly good way of actually getting them to stay in the game and do it. It’s also why upgrades to buildings, characters, vehicles, etc. are split into a lot of small steps.

I need to point out here that I, as a player of other companies’ games, actually enjoy this experience of feeling like I’m close to my big goal, only to realise that the journey was longer than I first expected. If I’m enjoying a good game (or a good book, TV series, etc.) I do not really want it to end.



Here’s a rough sketch of how the curves improve when adding features.

Most people will advise you to focus on retention first, and use a great retention as a proxy for player’s commitment to the game, and therefore as a signal for how much they are eventually willing to pay. Some suggests going the other way and using early monetization (players paying in the first week) as a proxy for their commitment to the game, and eventually their long-term retention. Probably either will work. However, there is some data to suggest that the later players start paying in the game, the more they will end up spending.

Also note that you would rather keep the players even if the do not pay, than lose them completely. Therefore, there should be no hard pay gates. A free player is a free ad for the game. A walking, talking evangelist with a network of friends to influence. In games where you play against others (PvP), the free players are also free content generators for the game company.

For a specific game, retention is likely to go down over time. For instance, in our Benji game, the one-day retention at launch was at 54%. Now, a few years later, we are tracking 35-40% for one-day retention, with all numbers measured on organic users. Where you get your users will have a huge influence on the retention numbers – but that is also for another post.

The same trend has also been observed by others.

One last observation: it’s likely better not to demand very deep concentration in mobile games. Deep concentration limits when people can play, which in turn makes it harder for them to form a habit around your game. It’s better to make the game playable with one eye while watching TV or your kids with the other eye. Console, VR and PC games will brag about how “immersive” they are. On mobile, if you’re immersed while waiting for the bus, you will miss the bus!

The challenge of giving away $100,000

This week, I’m going to tell you about a surprisingly interesting work-for-hire project and about how we failed with it. It’s surprisingly hard to market a competition with big prize money.

Every now and then, someone contacts us and wants us to make a mobile game for them. Usually, they back down after we explain to them how the mobile games market works – it will cost you more than $15,000 to make a game, and chances are that the end result is neither Angry Birds, nor Candy Crush Saga.

This time, however, we found a good fit with a game we wanted to do and the brand that wanted us to do it. We had an idea for a twist on the endless runner genre that we wanted to try out. The idea was to put the game under water, and then use ever-increasing currents as the main challenge. You swim up and down a river with a simple control mechanic, but the currents always affect you. They keep growing stronger and will eventually force you to make a mistake. A few years ago, I had sketched out the mechanic with the concept name “Sammy the Salmon”.

Endless runners are some of the most popular games out there on mobile – most likely due to their approachability. They are popular, but very hard to make any money on – in other words, they don’t monetise. If, however, the main point is to get visibility, we thought an endless runner was a perfect fit. Even more so when the client was called Mad-Croc (an energy drinks brand). With the same main idea, but Sammy the Salmon switched to a Croc, we set to work.

We first released the game at Gamescom in Cologne in August. We were curious to see if ads for the game printed on the energy drinks cans would drive traffic to the game. I can now confidently tell you that they do not, regardless of how many millions of cans that are sold worldwide. The really interesting part was, however, when the owner of the Mad-Croc brand wanted to make a huge competition around the new game. The basic idea was to say: whoever is the best player of this will win a hundred thousand dollars! Actually, he started off wanting to have a million dollar main prize – but we convinced him to try it out with just a hundred thousand.

Most of you have likely heard about e-sports being a really big and quickly growing thing these days. On the PC, there are huge tournaments and matching prize money. Some companies have also planned to bring e-sports to mobile, but it has not yet broken through for real.

Looking through the mobile competitions we could find, there were hardly any with prizes exceeding $5,000. Surely a $100,000 main prize would be newsworthy?

Let’s go just a bit into what we can call e-sports before answering that question. Most of the big tournaments on PC are played in teams. Is this a requirement for being a e-sport? I can’t really see why it should be. Among regular non-e-sports, there are, after all, some individual sports and some team sports. Why not try to make a humble endless runner into a sport on mobile devices?

We set to work building the required infrastructure to keep track of high-scores, writing rules and weeding out cheaters. We built this together with some partners. Our initial target was to launch during October, but we had to delay the launch until early December. A few weeks ago, we finally had everything set up and started running the tournament for four weeks (until January 2016). Here’s the game:

To make sure that this is really fair to players, we turned off all In-App Purchases for the competition mode. Now we cannot earn any money on the game, but it’s main purpose was anyway to get visibility.

The set-up and the level is always exactly the same for all players, and you cannot pay to get an advantage. What you can do is learn the level by playing it a lot as it does not change.

For added suspense, and to further discourage cheaters, we decided to name the best player of each week as a finalist. Then, by early next year, we will have four finalists that get to compete head to head at an event. This way, even if you could cheat your way into a finalist position, you would then have to compete for real, live, against the best players there are – likely a humiliating proposition. We have had some clumsy attempts at hacking our high score server, but, so far, we’re pretty confident in our anti-cheat technology.

When the competition went live, it was supported by an additional promotional campaign. While it was modest sums compared to the mobile marketing big spenders (we’re not talking millions per day here), it was still significant sums and partnering with some of the best marketing people in the industry. We messed around with a lot of crazy marketing material. This one probably being the silliest of the bunch:


So… what happens if you give a huge part of your marketing budget to your game’s superfans in a tournament like this? That’s how we think about the idea: give a large part of the ad budget to the players, instead of to the marketing agencies.

Actually, surprisingly little happens. Most people seem to think it is spam, and that it isn’t for real. Some of our silly short videos often get such responses. Perhaps it’s because no one has done such a thing before – people seem to associate it with the web pop-ups promising you that you are really THIS close to winning a million if you just click here, here and here. That means, that the competition was not deemed newsworthy by most media or by most people, and did not start rising up the download charts on its own or even when gently pushed by a marketing campaign.

The competition is still going on. We now have the first two finalists from the first and second weeks of December. Their high scores were within 0.2% of each other. There seems to be a max distance you can reach in the competition version of the game, and if you’re really good, you’ll get there in less than a week of playing. I wouldn’t have known that before we started as I’m not really good enough at endless runners myself. If you have some spare time over the holidays, and could use an extra $100,000, there’s really a fair chance of getting to the top of this.

And if you’re building a mobile e-sport with significant prize money, try to think about how to work around the problem of people associating you with spam. Maybe team sports are a better idea, after all. That way, players would at least have to spread the game to some friends in order to win the prize, which would give the game some virality that an individual game lacks.

Making Sense of Ad Networks

Ad networks, waterfalls and mediators and attribution partners

In an earlier post about SDKs, I wrote about ad networks. This post will expand upon that ecosystem.

It was likely simple once. You had a game or website with a lot of traffic, and someone wanted to show ads to all those eyeballs. So you did a deal. Like this:


Now there are three layers in between. At least.

The problem with direct sales are the communication channels. There’s more than one game with a lot of players, and there’s more than one company that wants to advertise. If everyone is talking to everyone then they all waste huge amounts of time just discussing and cutting deals. If a thousand advertisers talk to a thousand game developers, then there are a million deals to be made. Enter the ad networks.


The ad networks take care of this problem. All the advertisers just talk to an ad network, and all the game companies also just talk to an ad network. The ad network has made some sort of standard deals that they offer everyone to be efficient. Usually it’s some sort of auction that they are running.


Now, with a thousand advertisers and a thousand game developers, there are just two thousand discussions taking place, and they are mostly automated by the ad networks systems. Clearly this is useful and saves a lot of wasted effort. It’s so useful that more than one company got this idea! Now there are a few hundred ad networks around.

From the game company’s perspective, it is now a question of what ad network to use. Some of them have a lot of advertisers but pay only a little for each ad you show. Others have fewer advertisers but pay more for each ad. As a game company, you can make several times more money if you do the right choices with how to handle the ad networks.


The solution is to integrate more than one ad network into your game. Your game will then say to the ad network that “here’s a spot where you are allowed to show an ad”. If the network has a suitable ad to show, it is sent over, and they log what the user did (watched the video, clicked the link, or ignored it completely). Your game can basically ask the highest bidding ad network to show an ad first. If they have one to show, that’s great. If not, you go on to ask the second highest bidder if they have one, then the third and so forth down the line. This is called the “waterfall”.


Unfortunately, it’s a lot of work involved in optimising your ad revenue. Who has the best paying ads is always changing, and is different depending on what country your player is in. Which means that you have to have several waterfalls and constantly monitor and update them. Fortunately, there are now companies that offer this service. A mediation platform basically does this for you. There are several around, some run by ad networks (they swear on their grandmother’s grave that they do not favour their own ad network), and others from independent companies.

At the advertisers end, there is a similar problem. There are lots of ways to advertise your service or app, how do you know what’s the best one? You could be running small campaigns on each possible channel, measure how they did and then decide where to spend the big bucks based on that. This requires quite a lot of skill, math and time to do. Fortunately, there are companies who can do this advertising for you. Companies such as Fiksu and Twigeo are there for you when you want to outsource this job to professionals. To keep track of where you’re getting your installs, you need an Attribution partner, such as Adjust, Tune or AppsFlyer.

Now we are left with this picture of the market:


Currently, I’m mostly thinking about which network mediator to choose when we’re trying to make money from ads. You know, there are several, and we want to optimise between them…

And I have the same problem when wanting to buy ads. Someone really should offer me a service to choose between the service providers here…

Let me Spoil Every Movie for You

All Blockbusters have the same script! What can a game developer learn from that?

There are some good books to read if you aspire to become a screenwriter in Hollywood. A bunch of them all say the same thing: there’s a pretty fixed structure to the script of a blockbuster.

Let me spoil most movies for you now: when everything is finally going just great for the hero, pause the movie and you will most likely find yourself at the midpoint. When everything thereafter falls apart (bonus points if some minor character dies), pause again and your will be at ⅔ of the movie.

There are a number of books that will teach you the classic story telling model. It’s called “The Hero’s Journey”, and you have hopefully heard about it if you’re developing games with a narrative component (ok.. let’s say “story” instead). As a reminder, it goes like this:

Act 1:

-The story’s world is introduced. It’s in a stable state, we’re introduced to the characters.

-The theme of the movie is introduced. Hints about what this is going to be about.

-Something disturbs the stable world

-Our hero should go on an adventure, but hesitates

-A mentor comes in and gives our hero a swift kick in the behind, and the hero gets going


Act 2:

-Love story & side plots are introduced

-Our hero is trying to adjust to the new world and new rules. Likely feels like a fish out of water. Most of the movie’s trailer clips are from this part.

-MIDPOINT: our hero has finally learned the new rules and is victorious (but it’s a false victory)

-Problems appear, stakes are raised

-ALL is LOST! Something dies.


Act 3:

-Fresh inspiration allows the hero to find a new way

-At the midpoint, our hero had learned the new rules, but forgotten about his/her real self. With a new combination of the original personality and the new things learned, our hero is finally victorious for real.

-Ending with how the world changed as a result of the adventure. Everyone grew and learned something (except for the bad guys). Contrast the new world with the world at the beginning.


There you go: just about every Hollywood blockbuster works according to these rules. You can use it to annoy friends and relatives by telling them what comes next. If you want to learn more, here are some books about it.

Entertaining books:

Save the cat!

How to write a movie in 21 days


Serious (=Dry and Academic):


The Writer’s Journey

The Hero with a Thousand Faces


However, the point I’m getting at here is not the straightforward idea that game stories should be just like movie stories. Rather, it is that a related art form has developed some rules for what works. Rules that have had a remarkable staying power. You see, this structure does not only underpin movies, but stories overall. Joseph Campbell abstracted The Hero’s Journey by looking at stories in literature throughout human history, from early myths to recent books and movies. He found the popular ones so similar in structure, that they basically tell variants of the same story. Human psychology evolves very slowly, and therefore certain patterns appeal to us over millennia.

Likewise for other art forms: there is music theory and there are colour and composition theories for visual arts. The real point is that there is likely to be some design patterns for successful games too, and we need to discover them. We need to understand where to innovate, and what parts are so fundamental that fighting them is futile.

On mobile Free-to-Play (F2P) games, I believe that designing for short sessions, several times per day, every day for months is a fundamental thing that will not change (see the number of the beast post for more). How specifically to achieve that end is still likely to evolve.

We might also see more stories in mobile F2P games, but it’s hard to produce hundreds of hours of storyline cost efficiently. If we do see stories, I think they will likely adapt the TV series version of the Hero’s Journey. That is, they run several of these story arcs overlapping. There’s always one story about to wrap up, one under way, and one just starting. Some arcs are longer, some shorter, etc. F2P games and soap operas are both never-ending.

This blog is about what we have so far learned about making games in general, and mobile F2P games in particular. When reading about ideas and best practises, please think about if the practises presented are only the current fad, or are they the fundamental Hero’s Journey rules of our art form.