the one on the right is better, but both need a lot of work. you're shading the the bottom right corner and adding highlight to the top left corner. these are 2d ways of thinking. his head is representative of a 3d shape, with volume. You have to think about where the light is coming from, what surfaces it will actually hit from that direction, and what surfaces can't be reached by the light source. For a game, it's usually easier not to have such and extreme light source direction. A top-down light source is more typical. The body doesn't seem to be affected by the light sources. aa-banding on the hands and ?tail?

as far as character design goes, he seems to lack... well, character. He doesn't have a personality, he stares blankly into space. What is he? Is his head a rock and body a log? Do you have any character sketches to help us understand what you're trying to convey?

Upgraded: