Hello, colors you are using have very low contrast and they are very similar. This is why shading doesn't look right. Also you should determine light source and shade all parts accordingly (one highlight color, one basic skin color and one shadow color).
Work on some neutral color background (gray or some low saturated mid tone color) because this pink/purple is hurting the eyes and you can't focus on character colors (if you turn of that pink background you will see that his skin color is more green that brown).
I would personally remove black outlines, cause at this size you can use those pixels for details, but that's stylistic choice.
Those legs don't fit this character, they are too plain.
Hope this was helpful.
