Make it a shooting gallery style game. Get yourself some actors to put on costumes and play the bad guys, and then run 1 or 2 at a time through it. You could time them and give the winner a prize or something. You can have your bystanders (whores) and townsfolk too, if you shoot them you lose points. It's like one of those shooting arcade games, except it's real. Think of it like a haunted house, you pay to get in for about 5 minutes of actual fun. I'd throw down some cash to shoot some folks with a 6 shooter in a western town.
Have a costume contest for the best dressed.
Mad props if you rig up a tumble weed.