In this post, we'd like to delve a bit deeper into how we used interest curves to enhance the game without adding a ton of new features. This deep dive will contain spoilers, so please skip it if you want to keep the surprises for when you play the game.
Interest curves
An interest curve is a method to keep players engaged and invested in your game by creating various ups and downs with moments of excitement. We highly recommend reading "The Art of Game Design" by Jesse Schell. In short, it's all about pacing the game around a curve that looks something like this:
Curves for the game
We're planning to have different 'worlds,' each with 5 levels. If we overlay that onto an interest curve, a peak could be on worlds 1, 3, 5, 7 and so on, with each peak slightly higher than the previous one. If we were to rank them based on a score from 1-10, it might look something like this:
World | Score |
|---|---|
World 1 | 6* |
World 2 | 2 |
World 3 | 7* |
World 4 | 4 |
etc... | ... |
* Peak.
In our game, we will not end with a peak and you might wonder why we do that. This is intentional. Let me explain why, but first I'll tell you what this score represents.
How curves are calculated
Kabonk's core gameplay loop involves breaking bricks, catching power-ups, and overcoming obstacles (we call them Level Set Pieces internally). We assigned each of them a score based on fun, difficulty, and interest value. Here are some examples:
Item | Fun | Difficulty | Interest Rate |
|---|---|---|---|
1-hit brick | 1 | 1 | 1 |
Explosion brick | 4 | 1 | 5 |
Pressure plate set piece | 2 | 3 | 3 |
Zap power-up | 5 | 1 | 4 |
Points are from 1-5.
The numbers are somewhat abstract since they heavily depend on the level and possible combinations. But they give a good indication of when and where to introduce them. See also our previous update about the upgrade rework.
With this scoring system in place, we can roughly create a beat chart and make little adjustments depending on playtests. Q&A is very important because, for example, fun is very personal.
Interest curve-inception
So with all this, we have a good estimate of how our game looks. But these interest curves aren't just for the complete game. When you zoom in, these curves have little interest curves within them. For example, a world has 5 levels, and these need to be interesting as well. This is how our levels will be ranked in each world:
Level | Score |
|---|---|
Level 1 | 2 |
Level 2 | 8* |
Level 3 | 6 |
Level 4 | 10* |
Level 5 | 4 |
* Peak.
Like with the other interest curve, there are little peaks here, except we don't start or end with a 'bang.' The main reason is that the first time you open a new world, there is already the interest of the new and unknown, which is hard to balance. The reason we don't end with the highest peak is that it should be fun and exciting but not difficult. There should not be new mechanics, and players should use their previously learned skills to good effect. To have fun. If a player needs to learn new skills on the last level or it is too difficult, they might get frustrated. I don't want their last impression to be that. They should feel smart, powerful, and earn their fun, which they worked very hard for. So that is our reason for not ending with a peak of difficulty but a peak of fun.
More inception
If we zoom in a little further, we can and need to introduce an interest curve for each individual level too. This is all about level design and making sure you test, test, and test. Our Q&A findings showed, for example, that we should never end with the most difficult bricks at the very end of a level. It might seem obvious, but when you have been so deep in development, you can't always see that. Feedback is very important for that. So thank you.
It is more than just gameplay
So we have all power-ups, bricks, and level set pieces. A few small but very useful tools we haven't mentioned are achievements, unlockables, progress, and surprises.
We are planning (not officially announced yet) to add an endless mode. We believe it shouldn't be unlocked at the end of the game but rather somewhere near the end of World 2. Achievements, stats, and leaderboards are also a good way to keep players interested over time. Achievements are a useful tool when introduced at the right beat. Another aspect is surprises. They can even be shown beforehand by unlockable doors to keep players wondering.
There is so much more, but hopefully, this gives a little insight into the inner workings.
Until next time...
p.s. Zap power-up, what does that mean?
