Oh, you don't remember then. Well, it's a game of town vs. mafia. At its core, if you're town, you have to find and kill the mafia, while if you're mafia, you have to avoid dying and outnumber the town to win. Does that remind you of the game?
No, not a bit. Is it a web game or is it played in the comments of a thread somewhere? I don't remember ever playing it.