Amnesekai

"Your earliest memory is of an epic struggle where your life hung in the balance. This is distressing because that moment is happening to you right now. You must figure out who you are, what you can do, what your goals are, and how to stop being so immediately endangered and start endangering other people instead. 

The DM has your filled character sheet in front of them. You have a blank one in front of you. The goal at the end of the game is to have as much of that sheet filled out as you can and to not be dead. "