Cute game. I wish the tank turret moved full 360 degrees, and perhaps a bit faster.
At first, I couldn't figure out the objective in the game, until I noticed the help button. People are not likely to notice the help button, and even if they do, it's not a good user experience to expect them to do that. There were enough screens before the game starts to describe the objective.
Apart from these small nitpicks, a well-done 3-in-1 game.