zm_JumpRope, I think it would be amusing.
Take a look and consider adding this to the maps.
http://www.gamebanana.com/zombiemaster/maps/84850While the ZM changes the speed and direction of the 'rope' the players need to survive up to 25 jumps to win. The map chooses randomly on how many jumps should be chosen to win. There is 10, 15, 20, and 25 for the humans to jump.
I played this map before and i think it's funny so