I've got an absolutely glorious idea for a mafia game, with a setting toooootally unrelated to Paranormals.
1. There is a map that consists of 36 rooms arranged in a 6x6 square that wraps around both sides. At any given moment any given person is in one room (even if he is a corpse).
2. There is no day and night cycle. Instead, there is a non-extendable 24-hour 'turn' cycle. Once every turn every player has an opportunity to move once (unless he's wounded, but that's another story).
3. At the end of every turn, if half of the people alive (rounded up) are voting for a given person, he gets lynched. Otherwise nothing happens.
4. There are two dopps who move around in exactly the same way as humans and can kill the person they're in a room with. They don't have a chat and don't know each other's identity initially but will recognize each other when they meet. A single dopp can overpower a single person; two dopps can overpower three people. There are modifiers to this - i.e. someone may reveal the attackers while he's being killed or someone may be entirely unable to defend himself.
5. Some rooms contain food. Each food source can only be used by a given player once. It gives them nutrition enough for 5 turns, then they become wounded and can last three more turns before dying. If they're already wounded when eating food, they can last 5 turns before dying.
6. Some rooms contain traps. They consist of teleports, spikes-outta-floor, silencers, what have you, though I can guarantee there aren't going to be any insta-kill ones.
7. There is a high emphasis placed on the act of speaking - i.e. you can hide in a closet and someone who's in the room will only hear you if you speak, there are people who can identify people in the adjacent rooms if they speak and so forth.
8. There is no 'official' notification whenever someone dies. You will hear a scream (that may be modified by outside factors) and may find a corpse later, and that's it. No roleflips for you.
9. There is a 'wound' system. Whenever someone triggers a certain kind of traps, get affected by someone's role (the only truly insta-kill ability in the game is dopps' kill against a defenseless person), get weakened by hunger and so forth. If you're wounded, you will only be able to move once every two turns and anything that would wound you again kills you. Wounds may be healed over time, by certain rooms or by certain roles.
10. You will get a description of people's appearance, which may hint at what roles they might possess. No examples here.
And that's pretty much it. Join up.