You going for more of a realistic style or a more cartoony style? It's hard to tell due to the number of planes and shades you're working with on the character. You're shading him more like you'd shade an object or other more static scenery in the environment. Seems he would be difficult to animate that way (i.e. with too many detailed planes to keep track of) and the fact that you could utilize your style more efficiently (assuming the style is cartoony by judging based on its proportions) in order to make that animation easier and more charming (with less details to worry with).
You can do what you like detail-wise, but I think simplifying might be less work and require less overhead on the viewer's part with lower visual-density in order to interpret this guy is a chunky squat sort of cartoony dude. You want cartoony, then simplify.
If you plan to keep the overly-detailed coloring on such simplified proportions, keep in mind that it sort of creeps up into the "Uncanny Valley" side of the fence imo. See the "realistic super mario" or "realistic jessica rabbit" images on the web. Too realisitc-looking to be a cartoon, but too cartoony-looking to be real. The eventual and inevitable conflict arising in the viewer's brain tends to be quite unpleasant.
Just food for thought.
With that said, continuing on with your current image pixel-wise, your feet on the front view should have some light bringing the tips of the toes forward a little aligning it on the same plane as the rest of the guy (otherwise, the guy would fall forward).
Secondly, without some buffer-color (sometimes called AA) on the more rounded forms, your guy's back and stomach look like they've been sliced off with a large blade form-wise.
Finally, speaking of clarity of the forms, it's difficult to tell whether that middle section of the arms is the bicep or forearm due to the strangely distended shoulders (which also appear to be positioned too far forward in the front-facing image). Also, since your light source appears to be from the top, the top of the head on the front-facing sprite seems like it would be lit toward the back of the head too, with light gathering around the larger sharper ridges of the hair form (assuming the hair form is the same for the front as it is for the back -- my critique on this is based around the more clear back-view form of the hair).
