You need to work on your anatomy.
The way the hand wraps around the tree trunk is wrong, because you are not considering the fact the hand has thickness too, and with the way you have painted it, the palm would be intersecting the tree trunk. The fingers are also placed too uniformly and looks unnatural.
The size of his ankle is a bit too thick, even for a stylized figure, and the angle of the lower right leg is odd–pointing at a very uncomfortable direction.
The way his left foot is placed on the cliff edge is odd. Is the rest of his foot flat on the ground and his toes wrapping over the edge of the cliff, or is he tip-toeing?
Stylistically, the look you have is kind of flat, sterile, and without interesting variations like different surface properties, natural discolorations, color shifts, or effects of color bleed during radiosity. You also tend to render all turning of forms with almost equal rate, instead of differentiating between softer turns and sharper turns. You also don’t seem to have any intentional management of your hierarchy of edges, such as sharp, firm, soft, and lost edges.