Hey, Overkill.
Because of him being an even amount of pixels wide, one leg is wider than the other. Either make him one pixel thinner or put space between the legs or something. I dislike the outline between the shirt and pants. The outline makes it seem like the torso and legs are two seperate entities, when of course they are connected. A smoother transition would be more believable. Also, I don't like the pixels by the armpits. The make his torso expand awkwardly. Watch your proportions. His hands should go down past his torso to a little above mid-thigh, I believe. Either his torso is too long or his arms are too short, perhaps a little of both in this case.
Also, I don't think three frame animations will cut it.