As both a local multiplayer fan and an awful jackass who should never be invited to parties, I'm very much into the idea of Party Saboteurs [official site]. With similar ideas to Spy Party and Hidden in Plain Sight, it's a game about scamps and scallywags pretending to be NPCs and blend in with the crowd to can complete naughty missions without being spotted and killed. In Party Saboteurs, every player controls both a spy and a sniper at the same time, see, working their wickedness and trying to snipe their opponents. And after a stretch on Steam Early Access, it's now properly released.
So! Players are attending fancy parties in fancy places, and all of them are sneaky spies. You have simple objectives, revolving around interacting with items like files around the levels. Thing is, you can't rush the objectives because every player also controls a sniper watching over the party, waiting to pick off anyone who looks suspicious. Spy Party where you everyone plays both spy and sniper, yeah?
How does it work? Character selection is done by showing every playable character in the level, with a certain button assigned to each - so you don't know who other folks are playing unless you peep their presses. During rounds, the level is blacked out aside from areas shown within each player's sniper scope (you can remember where you were, yeah?). It looks a little something like this:
Party Saboteurs is £6.99/9,99€/$9.99 on Steam. You will need controllers to play. Heck, you can even make it eight-player if you share controllers.