I really like the concept of the game. It's similar to "basketballs", one of my favorites on here. Some of the levels do require some thought to complete. One suggestion that would make it better is to have some kind of power gauge for each shot. As it is, I think it's good enough to pass judgment.
You know what this game needs?
Neatly done, nice art, physics spot on, all in all to put it simple this game is sweet
Very interesting and fun to play.
Great game but you fail to instruct that the cannon's strength depends on the distance of the mouse from the cannon itself.