Rated M What if a Mortal Kombat video game gets too violent and too gory for its Mature ESRB rating?

Last time I checked the ESRB rating criteria, the only thing that can get a game the dreaded AO rating (Adults Only, the only rating above M) is interactive, on-screen + - sex   scenes. I admit that I don't know much about Mortal Kombat, but I don't see them adding that to the series. Especially since it would mean that most retailers won't sell (because at that point it's literally + - porn   ) it and it would be nearly impossible to get the game released on consoles (because, again, it would be considered + - porn   ).