GGJ 2012 Diversifiers :
Collaborative Casual/Hardcore: (Two players: one casual, one hardcore) Collaborative play for two, but one player has more to do than the other (or the difficulty level is different between them).
Hive mind: (3+ players control the same avatar) Player avatar is controlled simultaneously by 3 or more people. They don’t have to, but may, control the same aspect of the character.
I know what you did last…: (Game changes between sessions) The game mechanics or content will change in the next play session, based on the actions taken in the previous session.