I don't really have a complaint with the game, except that now looking at my monitor, I expect the display to be spherical instead of flat. No, really, I've been playing too much. The game's fucking amazing. The music is what really gets me goin'! Some of the boss music is downright epic and the levels' music is great! I'll probably do another minirip of songs from select levels.* Sucks that sound effects are probably unavoidable though.
*note: I know someone else ripped some songs, but they're all missing the intros and are otherwise sucky quality, so
edit: one of my favorite things was in the first area where you use the blue stars to pull you toward them-- on the first planetoid (the metallic square one), you don't have to use the stars! If you get the right momentum, you can actually slingshot your way to the next one with the gravity of it!
Jam it back in, in the dark.