You should over complicate this robot just for fun. Put it in a sphere that has a gyroscope in it, then put 1 track that goes all the way around the sphere with a wieght on it, then another one that's perpendicular and goes around the sphere as well with another wieght on it, and use that to control the way it moves. That'd be really hawt, and probably isn't *too* compliated. Only problem with this that I can think of is if the robot is ever on a slant of some sort.