Ok. Well the first thing that you may consider is that very small shapes may go without shading in some cases. As it stands you have some light reflections that seem too abstract to define the contours of your metroid. I assume you are trying to make somewhat realistic reflections and you may just need to shade less and selectively decide what needs to be shaded and what is too small to be accurately described by shading. The colors span the whole spectrum and this may make shapes hard to discern because many colors in a small area tend to blend together and add visual noise. When you are making a sprite this small you need to keep in mind what details need to be included and how to best represent your forms and surfaces. Visual clarity may be increased if you use lighter colors with bigger gaps between midtones.