UPDATE
Added more pictures.
I am aware that the 2 Call of Duty guys seem out of place, that is because I wanted to add something Call of Duty related to it. It's my sig on a gaming website.
The text doesn't seem that easy to read, and there's too much green. And looks like you used 1-3 brushes in it.
You should add some different colors and a variety of brushes to it.
If someone already addressed this then my b..
You should've just drawn one line for the body, lips, etc.. instead of leaving the sketch lines there to make it look neater, the shading looks fine but the color for the eyes looks a bit out of the line.
Unless there's black highlights in his hair I see no reason for the black outlines, Try using shades of yellow, if his hair is really that yellow.
His ears are pointed. (intentional?)
And his eyebrows are black? You should post the picture you were drawing this from.
The face needs A LOT more...