This is cool, I think this is a really good start, you have a fun interaction, and breaking the squares feels gratifying. I think that if you added more game challenges, rather than JUST collecting as many squares as possible, you could have something great.
Nice game. the mechanics are unique. I think the animations are slightly laggy (tested with my iphone 4s).
Also, the game crashed on me, but I couldn't reproduce the steps.
Think: obstacles, power-ups, extra time, etc.