The OneWheel operates based on balancing mass. So you put more mass on one side, the OneWheel moves that way. Put more mass, it goes faster. Some people drive using their hips (me included), some people drive using their shoulders (I don't understand why one would do this)

When you put more pressure on your back foot, it triggers regenerative braking. The regen brakes are actually very good. You can easily go from a pretty good clip to walking pace very smoothly and extremely quickly. Acceleration is almost instantaneous as well.