The best concept I've seen so far! Finished till the end and I'm proud to die 128 times! The levels were simple yet challenging with increasing difficulty. I got a bit stumped with piranha plants, especially the one surrounded by flames. Took me a while to realized and when I did, it felt good!
It might be just me but when I press R, the game freezes (HTML version). Might want to check that out. Also in the last level, if you don't get the rainbow thingy (what is that?) the round won't end. I know you intended people to get the rainbow thingy but I just like breaking games :)
The graphics are simple but very well executed. The contrast between the black and white world with the neon rainbows was a fantastic design choice!
I'm giving this full 5 stars, you deserve it!