Arrh, that sounds like fun.
I did a google search and there's plenty of good ideas out there.
I like the sound of these two:
Shark's Blood in your Drink: Freeze red Kool-aid or fruit punch into cubes ahead of time. You add these to Sprite, or whatever clear beverages you're serving, and they melt and slowly turn the drink to pink/red.
Hot Dog Octopus: Slice a hotdog lengthwise 1/2 or 2/3 of the way up a couple of times so that it has "legs". Present it as an hors d'oevres on a decorated tray, standing up on end with the legs splayed out.
As for games, I recommend "What Shall We Do With A Drunken Sailor?"; which I leave to you're imagination.