Solid.
I liked the "cheesy" plot you set up, and I liked how I could unlock new mouse dances and music to keep the game interesting, while still able to change them at my leisure. I found it difficult to get the mortar to go where I wanted it to, and would have liked a partial guide arrow to better anticipate where the mortar went, but it isn't really a "fault" that the game lacked it. I'd like to see more variance, like mice that moved around and were more difficult to hit, or moving obstacles so that more timing was required to hit the mouse. I'd also like to see ways to lose the game, like limited ammunition or a timer, because I easily beat most levels with TERRIBLE accuracy and I didn't see much of a challenge. The game was clearly well thought out and somewhat interesting, but was still quite short of being a great game.