I was rather thinking of having a detective mystery simulator where there's a medium-sized town with a whole bunch of radiant-style AI, and two human players. One is a serial killer that gets computer-assigned MOs that they must fulfill, and the other player is the detective who has to question NPCs to find the killer.
The neat thing is, there would be human observers who would be able to say things to the killer, with a mask that distorts it into groans and whispers. The brilliant part is, no matter what the observers say, it'd be totally in character for voices a serial killer hears.
Each game would be saved, particularly highlights, could be played back later. So, naturally, killers will try to set up complicated and bizzare plots, and detectives will try to do awesome things because if they do well, everyone will want to see the video.
It's important to note that there would be a strong narrative causality system, so that if it's two minutes in and the detective happens to run into the murder and whips his revolver out, there's a 99% chance it'll jam or miss, but if the detective just suprised the killer after tracking him for twenty minutes, beat him down with fencepost, and went for a cue-de-gra (or however it's spelled) on the murderer while he's down, then it doesn't matter how many HP he has, it's over.
I don't know how any of that could apply outside of the serial killer class. Maybe a Vigilantie class?