A profiler is extremely helpful when trying to figure out why you’re game lags. It turned out that all the collision checking done every frame was a huge bottleneck. And actually, most of the checking was unnecessary (do I really have to check if two wall instances collide with each other?).

Anyways, I’m mostly done with the mechanics (which really aren’t that complicated). I’ll add some more gameplay elements and submit the game with at least one completely level hopefully. But first, I need to catch some shuteye.