Just for an avatar
I really like this, the scale and detail is great, and it's very clean.
I think the only thing I don't like about it is the face, it's got an rpg style head, which is okay, but there's something about the eye/eyes that bother me, like they're too low on the face or something.
Good choice of colours.
Is that an arm middle? Perhaps it needs a sleeve to really show. Other than that I really like your understanding of shading.