Making a Hit Idle Game – Eight Lessons from Kolibri Games

In October, we held our second Making Hit Casual Games event, focusing on idle games (aka ‘clicker’ games). We wanted to know what made Kolibri Games’ Idle Miner Tycoon so successful. So we invited Kolibri’s Director of Business Development, Nate Barker, to tell our audience what lessons they learned from making their debut hit – and how they put them to use in developing their next big game, Idle Factory Tycoon.

If you couldn’t be there in person, here’s Nate to fill you in on all the idle games wisdom you missed:

So what is an idle game?

There are lots of different ways to answer this question. But here’s our answer:

An idle game is a spreadsheet with an interface.

It’s not a very fun-sounding description, but it’s accurate. The mathematics behind idle games are mostly similar.

You start out with a score or currency you can manually increase. In Cookie Clicker, for example, you click on a cookie to obtain one cookie. Dead simple. Once you have a decent amount of the game’s currency, you can trade them in for a resource that’ll boost the speed and ease with which you can get more of that currency.

And that’s pretty much it. You can find far more in-depth introductions to idle games and their appeal, but that’s the basic premise we put into practice to create Idle Miner Tycoon in 2016.

We started out as a team of 4, working out of a student apartment near Frankfurt. From these humble beginnings, we grew to a team of over 100, running a gaming franchise with over 100 million downloads.

Here’s what we learned from that journey.

1. Start with an idea that’ll stand out

The idle game format lends itself well to two things: business sims and tower building. So most of the market is based around one of those two ideas.

We went for a subtle difference. We took the tower building concept and inverted it – so instead of building up, you’re mining down.

It’s a simple difference, but it made Idle Miner Tycoon stand out.

2. Create a dead simple prototype

Our (seemingly unambitious) motto is: say ‘no’ to everything you want to do.

Whatever bold, innovative ideas you have for your idle game in the long term, say no and keep things very simple to start with.

We created a basic prototype for Idle Miner Tycoon – one that was remarkable more for what it didn’t have than what it did have:

• No 3D artwork
• No in-app purchases
• No social features
• No localization
• No ad mediation
• No long-term motivation
• No cloudsave

The prototype worked well, with outstanding D1 retention ranging from 63% to 81%. That’s the basis for a good idle game. (Most games have roughly 40%.) Everything else can come later.

By focusing on D1 retention, we gave ourselves more wiggle room for the later aspects of the game. If we got something wrong further down the line, we could fix it without affecting our D1 figures.

3. Don’t push on with something that’s not working

Our first project was called Front Yard Wars.

This game never saw the light of day. In hindsight, we can see three reasons why this project failed:

• We used waterfall development instead of an agile approach
• We had a very complex technical process
• And we did no testing on it for months

We’d completed about 60% of this game before we realized it wasn’t working. We could’ve pushed through and tried to get it finished, but we decided to scrap it and start something totally new. Based on the success of our next project, we’re very happy that we made the right call.

4. Show the core gameplay loop all on one screen

Idle Miner Tycoon has four stages in its core gameplay loop:

1. Mine
2. Transport
3. Sell
4. Upgrade

Our interface shows all these stages in one screen. And between each is a ‘choke point’ – a variable that determines how quickly you can progress. By upgrading, you can mine more resources, transport them faster, sell them for more, etc.

By keeping this process clearly visible, it makes the game very accessible. It’s something you can easily pick up on a 10-minute train journey and jump straight into the gameplay. And it clearly establishes the choke points that’ll become the basis of your monetization.

5. Base your monetization on ‘pay or wait’

You can’t lose an idle game. It’s all about how fast you want to progress. And that speed of progression is what players will pay to boost.

If you want to open a new mine, for example, in Idle Miner Tycoon you have two options:

1. Pay money, either by spending in-game currency or by watching an ad
2. Wait until you can unlock the new mine through the normal gameplay loop

About 60% of our revenue comes from ads. Our biggest source of ad revenue comes from players watching ads in exchange for boosting their mines’ revenues. Our players’ watch, on average, eight ads pers session, per day.

The other 60% of our revenue comes from in-app purchases. We initially didn’t have these, but our community told us they wanted a way to spend money to speed up progression. If we hadn’t been listening to our community, the game might not have been anywhere near as successful.

6. Use a lean development process

In 2018, we grew our portfolio to two idle games, releasing Idle Factory Tycoon. By this time, we’d learned a lot from developing and releasing our first game, so we’d honed our development process down to five steps:

1. We start with a small team, looking for a good concept and core mechanic.
2. We create a simple prototype, test and refine it.
3. Then, we test the game internally. Every member of the team plays it to decide how fun it is and to fix bugs. By the end of this stage, we’re about eight weeks into the process.
4. And that’s when we start external testing. We look at early day retention, organic downloads, ratings, and user feedback. This takes about four weeks.
5. Once we’re happy with the game, we’re ready to scale up. We grow our team, build more features, and scale the game with our increasing user numbers.

We base the process around the idea of ‘minimum viable product’. This idea comes from our main inspiration – the book ‘The Lean Startup’ by Eric Ries.

It works by never doing anything more than you need to move onto the next stage of development. There’s no point spending time polishing the graphics and balancing the numbers while you still don’t even know if the basic concept works.

Games are a hit-driven business. The faster you can figure out that a game isn’t working, the lower the costs.

7. Keep players engaged

Since we released Idle Miner Tycoon in July 2016, we’ve polished and expanded it with over 160 updates.

We try to put out one update every week. This keeps users really engaged because they get used to updates coming thick and fast.

The game’s expanded massively in this time. We’ve added features like:

• New resources to mine. In the start, players mined coal, gold and all the typical minable materials. After we ran out of those, we started adding more playful ones, like candy.
• New areas to explore. We added a world map to the game, with new locations to expand into and discover new resources to mine.
• Expeditions. This was our first foray into social features. Players can help each other on expeditions to discover new rewards. The more players team up, the less time it takes to get the rewards.
• Expandable skill trees. This is where the metagame began to take off. Players choose different power-ups to boost their in-game skills.
• Event mines. These are limited-time-only mines with fun, unusual resources to collect, like sushi, aliens, and pearls. Event mines would often double our revenue for a weekend.
• Season pass. We saw this working well in top games like Clash of Clans and Fortnite, so we added it to our game. Players buy a season pass to boost their rewards from event mines for a set time. This is huge for our revenue.

We use a four-day, staged rollout to fix bugs early and figure out what works and what doesn’t:

• Day one: We rollout the update to 1% of our player base. At this point, we’re looking for any major bugs or any major issues that would cause us to cancel the release entirely.
• Day two: We expand to 5%, still focusing on bug fixing.
• Day three: We go up to 20% and look for qualitative feedback and store reviews.
• Day four: If we’re happy with all the feedback, we make the update live to 100% of players.

And finally, listen to your players

We’ve grown our games by using data to understand our players. From this, we know that most of our players are in Europe and the Americas. We know they generally have play sessions of around ten minutes on average. We know we have 52% ad engagement. And we even know our players’ most popular first, second and third in-game purchases.

If we hadn’t listened to our community, we probably wouldn’t be where we are today.

I don’t want you to make idle games – I want you to make good idle games. We really hope our advice will help you do just that. If you have any questions for myself or any of the other speakers, you can ask them here.