maybe put the arms (+ shoulder pads) 1 pixel down and to the front, put the eyes 1 pixel higher and move the far leg in a bit, but only a bit, i think moving the whole leg a pixel would be too much.
put some hair on the lower bart of the back of his head

and sharpen up the dge of the axe, right now it looks a bit like a blow up toy, because of the heavy AA on the cutting edge
i prefer the 15 colour palette over the 16 colour one, but maybe change the metal hue to something more blue then purple.
and looking at it again, maybe lengthen up the arms a nudge and give them elbows =)