Posture customization: many MMORPGs / RPGs have this feature. But most if not all don't let the player himself the ability to make his own posture. Usually there are pre-made ones to choose. Won't it be interesting to see many people each of them with their unique posture. It adds realism rather than using a default posture. Imagine yourself walking on the street and all the people around you are different, not only their appearance but how they stand. It gives the game a better atmosphere. Some people might get concerned that people are going to get crazy using the feature and do some impossible (anatomically) postures. But usually you get limitation to how body parts are allowed to move. People might try to make some funny stances but you can do those in reality so why not adding this to the game. Moreover this might improve the game.