Couple things:
1) It doesnt look anything like yamcha. If it wasnt for the hair, he can be anyone. Work on the face a lot more. The nose is off, and the face is to long.
2) You dont need pupils to be able to deform in HL2.
3) The arms are really wierd, dont look proper. The shoulders are a little huge. Ure arms kinda look like this \_ , u should still have a arch for the shoulder, but not that huge. I hope you understand what im trying to say.
4) The shirt looks really wierd. With 2800 polys, you can add alot more details to the shirt. It has no wrinkles or anything. If your going to add details, detail that, not pupils.
5) Im not shure, but are the neck and shirt even connected? Those jagged lines dont look like it does.