Good little game :) The art is charming and the sounds are good. I'm really happy to hear you got your daughter involved in the game making process!
My biggest issue with the game is the fact that the camera follows the mouse instead of the player. This leads to some very jumpy, nausea-inducing movement.
Like Ereborn said, it would be good to have an indicator of why we change levels and how long until the next one, whether it's time or number of enemies destroyed.