I am just too bad with platformers. :(
Anyway, cool design and nice controls. But here come the suggestions: The option to restart in the level where you died would be nicer for casual players like me. The animation and sound effect when dying was a bit too lengthy for my taste (maybe only because I died so often? ;-) Also, the sound was much less cool and more retro than the graphics, so I felt this didn't match as well.
Haven't tried multiplayer mode. That's a nice feature!