I agree with styxtwo. Bouncing one ball gets really easy after a while, and there's not really any incentive to try bouncing more than one ball if your scores only increase linearly. A pause button would be nice, too
I agree with one of the other commenters, that keyboard control would be useful. It's annoying when the mouse goes out of the play area, and you have to try to move it back in again quickly enough to not get killed. This is the first time I've seen breakout with irregular shapes though, which is interesting