If i had a 6 year old kid, i'd let him play GTA/Fallout 3/Gears of War, well pretty much any kind of game he would want, i wouldn't meddle with like asking why he likes it or not or forbidding a certain game.Also i would probably ask him to do something 2 mins prior of me wanting him to do something, but still pretending his late (so that it doesn't get to his head and starts schemes of his own), the only thing i would do though is make sure he knows game=/=real life. I grew up playing Doom, Heretic, Duke Nukem 3D, GTA and although my jokes seem awkward sometimes in the later years, i never went and stoled someone's car or believe in demons or tried a round house kid on a kid just cause i saw it in mortal kombat and as a child i was a pretty much a regular good kid (well at least till around 13-14).