Two things
Firstly, your choice of background is horrible. It's highly distracting, and annoying to be staring at. Change it (at least remove the white). The colour scheme is also weak, but doesn't necessarily need to be changed.
Secondly, I had one glitch (only one, that's pretty good) and it only happened once, where the ball went to the left side of the screen near the top, and instead of bouncing, it just shimmied down the outside edge. Don't know why, don't know how.
Overall though, this is a smooth game. Some minor improvements, and you've got a decent version of a game that's been done many times over.