I'm about 15+ hours in and starting to lose interest. I love the visuals and the OST, and I appreciate all of the content packed into the game, but it can be so damn boring. I feel like I'm just holding down a shoulder button as Italian Spiderman does all the heavy lifting for me. I've haven't upgraded my armor and I've avoided even repairing it, but it's still absurdly easy.
This was an issue in AC1 & AC2, but it's even more apparent now that you have kill streaks and fellow assassin's to summon. I'm not even saying the game needs to be hard, but some resistance is necessarily for me to feel some sense of satisfaction. It's all style and no substance.
It doesn't help that the missions, aside from the cool crypt stuff, are kind of lame. They usually consist of hauling ass from a to b then effortlessly wiping a few dudes out to win. I go out of my way to make it more challenging, like forcing myself to only use the poison blade, but it's not enough.
Oh well, it's still good for something to chill out to. I highly doubt that I'll have any interest in Revelations, though, unless they decide to overhaul the core mechanics (yeah right).