forum mafia or similar (like a very slow game of Town of Salem) with a custom, mystery roleset where all the game text - instructions, roles, descriptions of roles, information you're given, "x player has died", everything - is written in an alien language (relatively simple conlang) that you need to learn to translate while playing in order to work out what your role is and what team you're on and how you're supposed to vote to execute and what the heck is actually happening
