Very nice, got to lv 18, then decided to give up
This game is rather nice, but I could suggest some differen things, like stages with limits(electrified siddings, touch it you lose one life) or difficulty settings(easy: 1 by 1 added, medium: start with 2 black balls, +2 per stage, hard: start with 3 black balls, +3 per stage)
and maybe a background music would let me stop using media player for a while to get myself more entertained while I play this. otherwise, very nice, you should also make a ready button or pause button so someone can take a break.
btw, a small prize for clearing all the stages or something would be nice(if you go for a difficulty setting, dif sweeter prizes for finishing the harder difficulties would be very nicely appreciated)
these are my suggestions, anyways good work, very nice