Assassin's Creed Revelations came out today and I'm still half a game behind!
I want to finish as much of the side stuff as possible, but I also want to get through the rest of the main story line quickly, so that I can play the new installment of the series without spoiling the ending of Brotherhood for myself.
Is it possible to go back and keep playing to complete guild challenges, side missions, etc. after the main memory sequences are completed or is it more like the original Fallout 3 where the game after the last quest in the main quest line?