I really can't understand all the hate for this game, with people saying it's the worst in the series. I mean it improves most stuff from the earlier games, Connor's story is pretty good, the multiplayer is still fun and has a cool idea behind it. I played through on PS3 and had almost no bugs or glitches. Yeah Desmond's story was kind of stupid, but they have been stupid throughout the series, the real good story has always been that of the featured assassin. AC2 and Brotherhood are usually said to the best before 3 came out and neither of their desmond stories are good. In 2 Desmond barely does anything except realizing that he has parkour skills now, and in Brotherhood he still does nothing then gets possessed and kills Lucy, these aren't strong story lines at all. The modern day stuff is just a vehicle to deliver the historical stuff.
So besides the ending, what makes this game so hated? I loved it and thought it was a true sequel that totally delivered.