That was his face being a combination of desmond, ezio, and altair. At the end of revelations when he gets out of the animus you see his face is back to normal. Its because his psyche couldnt determine who he really was that he looked like that.

i didn't know a combination of Desmond, Ezio, and Altair looked like Adam Sandler

I liked the change, I knew Desmond's face was slightly elongated....but I thought he looked very realistic, and the change in his facial details puts a sense of distress and awe into his character.

sorry maaan, i dident like it at all. to much details, happend with gears of war 3 too. to make the face look much more realstic is cool but it dosent feel the same to have played all 3 games then just suddenly change it. ofc it looks more stiff, but hey works for me

I didn't notice as many changes in Gears 3...but I am an artist in my prime, and while although I'm no game designer, I still have a fine appreciation of detail.