I'm not sure why you wouldn't expect this; you're transferring energy into a motor, so it will either need to gyrate in place, or accelerate downwards or upward

I'm not sure why you wouldn't expect this; you're transferring energy into a motor, so it will either need to gyrate in place, or accelerate downwards or upwards up a hill. Is it a surprising a snake can move without legs? It can't if it is dead. It needs to expend energy. This ball shaped thing isn't moving without use of energy, and isn't that surprising.