Some of my handy work.

[Devicho]

I think the biggest issue is with your shading. On the first sheet, everything appears to be pillowshaded. You need a defined lightsource rather than having the light come from the center. In the third sheet, any part that is white is also pillowshaded. The usage of dithering doesn't look very good and solid shading would look much better. Also, in the pose where his legs are going two different ways, the shading contradicts itself.

I'll leave it at that for now to keep this from being tl;dr, but if you can fix up the shading I'll go on.