First, I have a question: what engine are you doing this animation in? It looks very similar to the Half-Life 2 Engine that I did a few videos in when I was in school.
As for the trailer itself, it's a bit too long for it to be a trailer. You have a pretty big dialogue and static scene towards the beginning where it's your main character talking for an unnecessarily extended period of time. For the voice acting, there is a bit of popping sound. Try recording the dialogue without having the microphone near the voice talents' mouths or use a filter of some sort to solve it. Lastly, there is a lot of weird movements and "clipping" during the movements. I've worked with something similar to this when I did my projects with the Half-Life 2 Engine. The movements are very limited, which sucks, because the movements always seem "robotic." I imagine there's nothing you can solve the clipping problem but if there's a way you can avoid it, give it a shot. I think it'll clean it up a bit.
Apologize if my critique sound harsh. I just think you have a good idea going and what you can do to take it to the next level.