The game is really fantastic. Was disappointed with AC3 but the naval combat in this game makes it a whole lot of fun.
The issue that I've run into is:Warning: Spoiler! (Click to show)
I almost finished the game - killed Torres in the Observatory. Immediately afterwards, I spawned in the Abstergo office but the secretary lady told me that Olivier wants to see me. This was the same scene as before where you go up to the office and he asks to speak with the lady alone and you snoop in on their conversation by hacking the camera.
From what I read, you're supposed to spawn in the Abstergo office right after killing Torres where the "Sage" is about to inject you with something and then gets shot.
Now, I am stuck in the office and can't go up to the CCO's office (it asks me to go to his office but the elevator doesn't work)!
I tried hacking a bunch of computers and that works fine but I seem to be stuck there. If I try to go back into the Animus, it just spawns me in front of the elevator in the office!