It's a really cool idea. It drew me in. I do have some feedback. First of all, the graphics. Sometimes the shapes don't line up exactly, and they are quite simple. It might be fun to use pictures instead of just shapes, like jigwas puzzles but with all the operations. Secondly, I think the difficulty goes up a bit too quickly. The level with two operations is already quite hard, and after that you go straight to 4 or even 5 operations. I think it would be better to stay on 2 operations for one more level, then go to 3 and go towards 4 or 5 in later levels.
But very solid game!