I have just written my first 24 hour game, entitled "Witch", about care givers (aunts, nannies, starship artificial intelligence) who try to murder the people under their care. Think of it as a kind of My Life With Wicked Stepmother. It's an attempt to create a horror game which doesn't facilitate illusionism.

The game uses dispenses with a traditional GM, having the witch and the victims take turns framing scenes. It uses a conflict resolution system in which characters attack or try to heal each others attributes. It uses an innovative awareness mechanic to create dramatic irony. I think it probes the darkness of the human experience in a way that, say "Empire of Satanis" doesn't.

You can find the PDF at http://www.1km1kt.net/rpg/Witch.pdf

I'm early seeking comments, suggestions, etc.