It would be better if you animated the gun so it kicks up a bit, (more realistic).

 I think the shade dropping on the ground from the rock should be more to the right.

 Hmhm.... the shading on hair and on the chair's leg is the only thing that bothers me.

The shading could be different to make the ''skin'' if i can call it that way more textured not plastic. Right leg looks weirdly, if i understand right you tried to make it so it looks like he's in the process of walking? 

 Shading on sand could be more umm ''sandy texutred'' .

 I like the bottom part (legs) and the arm movement starting from arm joint. But everything else seems to be too still. I think it would look better if the umm... sides of the body would move a bit, shoulders etc.