The neck helps but cut the head bob back some. The concept of rendering a nose seems to be an eternal challenge for pixel artists but its always going to have that babyface look without it. To get an implied nose try breaking up the symmetry of the shadow under his eyes, make it look more like shading and less like a crease in his face.
Are you intending to make a template here or a character?
There is a lot of character to put on a face, for example I added the nose in that edit, and also widened the mouth a bit and that changed the character of it a lot.
If its a template I would just leave a space for a nose and not think about it too much. That way if you were to make characters out of it it kind of forces you to think about that space and make it distinct each time.
The legs still look a little chubby, especially around the calves on the back of the step. Taper those down, and make them get smaller on the back of the step to give it some depth. Also his right leg and foot seem to be pointing inward. I would point both of the feet away from the body a bit more and that should look a lot more natural.
