Fun hack, but my cat would methodically disassemble that little robot piece by piece. The little mongrel chews through ethernet cords and has zero tolerance for anything that moves and is smaller than a human. Evidence the flying leap from the couch that took out my U-Control gyro-copter.
Amusing. I guess the next step is to simulate the feeling of the pressure of the brush, so you know for sure that you are indeed brushing the cat. If this can be done, the next step of casual gaming will be amazing.