[Zathris]

I'm not really the kind of person who likes the idea of achievements BUT they could be used in this manner. Think of if you killed a certain ammount of players or innocent NPC's. You get a sorta small achievement with it that allows you to add new looks for your avatar such as darker eyes or a wider grin and scars.

A fun way to unlock things but still not really the best of ideas.

The best I woudl say is simply add a skill system for changing a characters looks (E.g. Star Wars Galaxies before they made it ****) Another way players can make money.