Jester15545, I assumed something like that would be included in the game. Was using it only as an example for a type of "combo". Do I have to pay royalties now? No? Phew.
Hmmm, well I'm going to elaborate on the Jello Gun a bit. Instead of it being just a Jello Gun, it might be called a Zoot Suit Riot Gun. Basically it turns their skin into whatever ammo you have on hand. The cheapest type of ammo for it would be the Jello Square. From there, you'd have Jello Shots (lol) which would leave them drunk after they manage to get free and they might attack their own peeps. After that, you could buy Rubber Chicken Suits (shots), which of course could be set on fire. The benefit is that they think they become a chicken, making them scared of their own shadow. Cluck Cluck. How about Mad Cow Steak Balls for ammo here? The other enemies start cannibalizing the target and start to go insane, or even turn into cows themselves. Just to taste how far this gun can go, you shoot rocks with it and then the target becomes a living boulder which crushes the other enemies. Or Pinyata Ammo where the other enemies start beating him to death trying to get candy out. Not too hard to get really creative with something like this.
Other weapons that I can think of are things like ultra high pressure water gun which melts through things that lasers can't. What about those tasers that shoot out wires? A cheap alternative to the flaming rubber chickens would be flaming tennis balls. How about a potato cannon? Or a supply of fireworks to blind/scare/entertain the enemies?