bullets
Felt it was pretty easy at first, but it got pretty hard towards the end.
It would be pretty nice if you could skip levels after a few tries and come back to them later, would make some parts less frustrating.
Also, I noticed that your ball doesn't quite move in the direction of your mouse if your mouse is at say, a 30 degree angle to it and quite far away. The ball moves vertically and horizontally at the same speed in this case, and reaches the mouse on one axis long before the other axis, when it shouldn't. It's hard to explain... but you gotta fix that.