excellent for a quick play :)
i got a bit pissed when i saw that levels 2.1, 2.2, etc were the same from level one with changed obstacles... i would have liked to see more variety in there.
the game itself is excellent, the graphics were nice but way too repetitive, i was getting bored of seeing the same pipes and blocks from the start of the level... it would appeal more if it hade more variety, maybe different obstacles and platforms.
about the music, i loved those remixes, but i use headphones and the volume is way too high, specially that sound when you hit the blocks >_< needed an ON/OFF switch or a volume slider maybe...
finally, i found some glitches in the menu... maybe its just me but none of the butons worked there aside from PLAY and the INSTRUCTIONS and CHARACTERS butons... inside of these 2 last mennus i could do nothing, if i clicked anything they just slided down again to show me the main menu...
overall good. i would love to see the next bullet bill with more variety :) i mean, this one would be okay if it had less levels but 4 level desings repeating themselves 8 TIMES? the cool thing was the boss at the end of each world but i did not have enough patiente to play the same levels to get to it...