I was thinking about an Eden of the East themed Mafia game. This lends itself for a variety of options.
For example, regular Mafia with a little twist: everyone has the same role. Namely Inventor - as in, you get a bunch of options each night, and everyone has the same options. Twist: You start with limited money, like $20. Each time you use a role, you pay $x, whereas x depends on how good the role is. Cop could be 5, Doctor 4, Framer 2, etc. And when you reach $0 you are automatically eliminated from the game. Balance problem is the Cop, obviously, which would be excluded in this set up so you don't get everyone copping everyone else at the start of the game and cruise control to victory. Probably other roles that are problematic for balance but I'm sure some quirky stuff can be thrown in to keep it diverse and fun.
Additional ideas to consider while keeping it in the Eden of the East theme are:
At the start of each day, each of the players' actions are publically posted, so that everyone can track what everyone else is doing. Of course, it'll just say, "Selecão XI" or something, and it won't be published which player is which "Selecão", nor will it be possible to request that information at night. Obviously this has implications for scum and town alike in what actions to take at night. In this setup it'd be possible to remove your actions from the log for additional monopoly dollars.
Another idea goes less into Mafia and more into "Last Man Standing": everyone's a Survivor. Everyone. And you want to kill everyone else. However, you may team up with others and send them messages at night (all through the moderator) for moolah, or maybe purchase masonry. Except you only win when you're the last man standing, which makes it a little problematic when three players are left - after all, no mislynches, so what do when two are left standing and you can't get majority lynch? Obviously this needs some solution beyond "add Vigilante to night options", although it'd probably work... Last Man Standing between two'd probably go into "do I bulletproof myself or attack the other?", then watch who runs out of money first... Well, whatever.
Would anyone even want to play that though? I guess I was just bored and thought of it, since themed games seem to run well lately. Completely standard Mafia with roles is also possible; everyone having a role makes the Selecão work, but there's a bunch of supporting characters who could do well with either no role or maybe a quirky minor role for flavour shenanigans.