I think a jump rope would be very fun. The rope could start swinging when you "use it" then press the down arrow to get it going, and the space bar to jump over it. Special tricks could be implemented with the up, down, right, and left arrows. You could also get a long jump rope for a glitch to hold each end and a third to jump, and use two long ropes at the same time for better tricks. The jumping glitch in this case could use the right and left arrows to move each foot independently and the space bar to jump with both.