I love the characters, they're archetypal, but not stereotypical if you understand what those mean.
Elena isn't the stereotypical video game woman. She's smart and tough, but not some overly sassy caricature. She's a career woman with a purpose. I like how she comes across as being able to handle herself, without going into those annoying stereotypes of the brutish, gung ho video game female.
Same for Nate and Sully, they both follow archetypes pretty closely. But have enough life to them that they have their own personality.
Oh, and the acting, wow, kudos to the whole acting team on this one. If this was a movie, it'd be on the level of Pirates 1 in terms of acting, better than just your average summer blockbuster. I love the making of videos that show the cutscenes being made.
I'm all for digital actors, but not for everything. Still, for productions where the character models are so complex, digital actors with mocap is a good way to go.