After having watched the gameplay vids I have to say that I loved the graphics. Everything looked sweet, except one very important thing. The transitions between the animations!
In the vids, every time you give a new movement command to Sam, the animations just "clips" if you understand what I mean. As if you created one "standing still animation" and one "walk cycle", and then just flip between the animations. The transition would be the thing that turns the character around, and initiates the walk cycle.
Because of the seeming lack of transitions, it becomes very obvious that the characters are not "real". I do know that it's very hard to create realism in 3d, especially in a game with a lot of freedom, but come on - you've chosen the 3d environment and we're in 2006 now.