I wanted to make a game that would be simple enough to play, but tricky enough to hold a players interest. I also wanted to make a game that would be replayable and could have a 'beat my score' aspect between friends.
After considering other ideas (i.e. side-scrolling R-Type games), I decided upon a game where you play a cat, using the left and right mouse buttons as the left and right paws, respectively. The base concept is simple, but could be built upon to become quite complex.