Hey, looking good.
I would say at that resolution should be fine as the sprites scaled up but I definitely think it needs more detail when it comes to the clothes. There are more curves on the legs and arms than you have. and so adding that and shading would do wonders. I think this would take care of the square limbs.
I tried to edit it with the details I was talking about, I hope that's OK!
Also having the curvature with the joints should make animating easier as there is more of an outline of where to go.
