I only know the real boardgame, and it's fairly simple, but enjoyable. Not sure how suited it is for async play though, because it's co-op and doesn't have much to do in a single turn... :/
Yeah I take back some of what I said about FI. On normal difficulty with random roles imo it's still quite challenging. Plus the achievements are good -- don't know if I will ever be able to beat that game on Extreme or whatever. Kinda wish Ghost Stories had achievements too so I could log my rare triumphs in that game.