Ball power up
The ball power up only makes the balls appear in teh center, which you can't get to most of the time. You should make it so the balls appear in the same x value of the paddle, so we can catch it more often. 5/10, as I get bored quickly with this genre of gaming. However, it is good for it's genre.
It's an alright start.
I really love these break-out style games but your is just lacking a few things.
Sometimes I felt like the ball physics were, the power-ups were not that fun, and the way you built the level doesn't allow enough room for the ball to get above the blocks and bust some of them out. If you fixed these things it would be a hugh improvement.
Needs some work
It's a start at a game. Need to polish up your collision detection and ball movement. Also some major slowdown happens with just a few items on the screen. Look through your code loops and see where you can improve performance. The balls only bounce off the paddle and bricks (no ball vs ball bounce) so you really should be able to speed it up. Many other bugs and overall random feeling of controls make this not to fun to play.