On level 21 I'm noticing that when the red guy and the purple guy land on each other, the red guy drags the purple guy slowly down toward the ground. Is that a) intentional, b) physics weirdness, or c) level-specific positioning weirdness?
Well, someone else commenting on this mentioned that if you jump while this is happening, you can sometimes get them to reverse, so the purple guy is pushing the red guy upward. So I don't think it has anything to do with weight. I'm honestly leaning toward b (some slight weirdness in how the game physics were implemented).