Nice to see you submitting some of your work!
I am guessing that the wooden texture has been added with a layer mode. I would instead break it into smaller parts and then merge the layers to set the mode afterwards. There are certain places, like the hand's palm and the fingers, that do not follow the curves correctly, making it suddenly look unrealistic.
You could also use an eraser for the parts like the eyes and the cracks, to remove the wooden texture from them, as the latter lose their meaning of being cracks and the former is becoming blurry.
Additionally, the crack on the chin that begins from the lip should really have another brush, because you left a circular edge on it, denoting what point you started drawing it from.
Finally, the arm screw could have a little touch up, so that it follows the lighting. Right now, the lighting comes from the right side, when that part should be the shadowy one.
The concept is really nice.
