Not sure what ages you are looking to target, but you could set up a platform about 3' tall the kids could stand on, with a hole cut in it. Through that hole you could have the kids "bait" and setup a tipup, and then set it. From behind you could trip the flag and attach a prize to the "hook." Then you could have the kids pull the prize up, perhaps with your helper offering a little fight or resistance.
This would probably be hard on the backs and knees of the staff though. It would give the young kids, probably up to around 9 yo, some fun.