Very simple, yet addicting and challenging game. :D
4.5 only though because the physics sometimes is kinda exaggerated? A simple push of the left/right arrows already makes the pieces move, as if it's slippery or something.
The simple graphics and sounds/music are fine, suits the game quite well, but for "kid" players, they'll easily get bored with that, but, we can't please everyone now, can't we?
Good job with the game. :)