An open world third-person game with RPG elements in the mold of GTA:San Andreas, with a Wild West theme, done relatively stereotypically, but not comically.
Based on your actions, you become an outlaw, a sheriff, a cowboy, a trader, or an explorer, or a mixture of those roles. Possibly a parallel development thread in an Indian tribe, too.
Wanted level is permanent and only reduced by doing time or by compensating with good deeds: becoming a deputy or sheriff; "cleaning up the town"; ...