Sorry for the title! I just have an idea of making a metal robot like the BattleBots in Robotica, but not remote controlled. Add some sort of IR "Lock On" system and it keeps following and hitting the target until it is destroyed, burnt, shattered, etc. Something like this.
servo1 = full_speed;
servo2 = full_speed;
servo1 = servo2 = full_speed_reverse;
It would be more complicated if the target was movable I think!
Just a thought. It would be fun to have a robot smashing things. Or have it follow and hit your cat.