These are my immediate gut impressions --
1. The green of his coat seems a bit bright. To the best of my knowledge, the German uniforms were a darker gray/green. For future reference, I think this shade would work for US uniforms. The pants also seem a bit too blue, but that could be the lighting. If you painted the pants a deeper gray/blue (heavier on the gray) and drybrushed with the base color you have here, I think you might be ok, or at least closer
2. The white in the eyes is too stark, which is a very common problem, and easily fixed (so I've read). I wish I could make suggestions here, but I can't get them right either. There are mixed opinions on whether small figures are easier or harder.
3. The clothes and skin are glossy. Skin has a sheen only when it's wet or dead (after death the skin tightens giving it a 'waxy' appearance). There are very few fabrics that are smooth enough to 'shine', and military uniforms out in the field definitely won't.
4. It could be the lighting, but I don't see much use of washes or drybrushing to create shadows or bring out highlights.
