Cool use of the theme! I agree w/ Lanyard on the mechanics bit, takes a little trial & error to pick up what you were throwing down. Not a huge deal, though.
I love those parallax layers back there, but it's easy to lose appreciation for them with the character being fast-paced like that. This is not a negative, just something I noticed because I really like how the lighting effect was done in that background.
Regarding controls, just FYI, it didn't pick up my controller. It's a typical Logitech USB Playstation II-style. Keyboard was fine, I just mention this because the game explicitly mentioned controllers.
Only other thing is I noticed you don't have to press a jump button for each jump, holding it down will repeat the jump. Pretty minor, just slightly counter-intuitive to me.
And my favorite facet of a game, to the point I think it would make a good category--atmosphere =D. Awesome job there, 'nuff said!