I like the Find the Bats Idea Fun Halloween Game Ideas.donut game is cute and choosing a word that's off limit is fun, adult version could be to take a drink every time you get caught saying the word :)
Dracula's Dentures - made from chocolate chip cookies, red frosting, and marshmallows. I'd use homemade chocolate chip cookies (or Enjoy Life cookies), Dandie mini marshmallows, and India Tree natural dyes to make red or pink frosting.
Easy Halloween Eyeball Recipe ~ These easy cheesy eyeballs have a simple list of ingredients: Mini Babybel cheese, black olives, ketchup, and red gel food coloring. I think I'd not use the ketchup and use all olive.