Vague not-necessarily-would-be-fun-to-play example sketch of a Mafia-format-but-not-Mafia game:
Each player is secretly given the names of two (alternatively: three) other players, each labeled as Love or Hate. You might have two Loves, two Hates, or one of each.
Each player is also secretly given a codeword, which is a moderately common word; something that wouldn't stand out as exotic in ordinary conversation, but isn't so common as to be easily overlooked by someone who's specifically looking for it. (Alternatively, maybe each player chooses their own codeword and privately informs the mods of it.)
If you mention your codeword in a game post, the next person who gets mentioned by name by any player (including by you later in the same post) is secretly marked for death, and the mods will announce at a random time between 24 and 48 hours later that the victim dies; the victim is eliminated from the game as of the mods' announcement.
The game ends after two weeks realtime. There is no night/day cycle. Nobody has a private communication channel.
You win if, at the end of the game, you and everyone you Love is alive, and everyone you Hate is dead. Otherwise you lose.