Haven't finished the game yet, but I am enjoying it so far. I do have some issues with it though...
The damn synchronization... I hated it when they introduced it and boy did they make an effort in this game. Previously you had a few objectives, mainly one per mission (or section), but in this game they throw, give or take, a thousand objectives. No matter how much they try to disguise it, I can still see the red flash in the corner of my screen. It bugs me. I know it's only "additional objectives" but I still try to obey. This time around they just went overboard with it. I'm already limited in my approach to the targets and the synchronization only limits me more. I wish they would go and look at AC again. I loved that I had to find out my targets whereabouts and had the opportunity to scan the area beforehand, check out guard locations and my escape route. It felt more... assassin like.
I also miss the vibrant renaissance cities; being able to run long distances on the buildings and reach ridiculous heights. I understand it's not possible in this setting, but I miss it nonetheless. The trees are fun, but I still miss big cities full of rooftops made for me. I have no beef with Connor, he is starting to grow on me.
I have to disagree with most here about the guards though. Yes, they are many but I enjoy the challenge. In AC you had to watch out for them, but from AC2 onwards you really didn't have to worry about them. If you just reached around the corner you were more or less invisible again (the yellow circle was tiny compared to this game). Which doesn't really make any sense if you think about it. I must admit though, that the guards in this game have ridiculously well honed eyesights. And they are very suspicious. And it does seem a little strange that I'm an enemy to both factions. Seriously, I helped you to get the fort and as thanks you shoot me? Okey...
I like how the free running has been improved. It is absolutely fantastic that people do not make me fall over anymore (or at least has not happened yet). But I don't understand why they took out grab (when falling) and ledge grab/kills. Could be that those are introduced later, as I said, haven't finished the game yet. Or it could be a bug, of which I have seen quite a few in still instalment.