Now our game is really playable, we can detect when the bullets touch the asteroids and destroy them; additionally, we have to be careful because our ship can be destroyed by them as well.

We have learned how to do simple collision detection with rectangular and circular bodies, adjusting the body for each particular sprite.

We also learned some optimization techniques for collision detection and implemented one that makes use of spatial partitioning.

The next step in our roadmap is to add some juiciness to the game. Didn't you notice that the asteroids are missing some explosions? In the next chapter, we are going to talk about how to create particle systems for effects.