I was the UI programmer and I really love how the mouse came out, as well! One of our optional goals was to include a tutorial, but we ran out of time. The game is based on "powerups" that you have on the left side, and you can give them to cats by selecting a button and then clicking on a cat. The levels use different powerups to allow the cats to get to the goal! I'll add that info under the description of the game so that other folks can also understand, haha.