Ah ok, robotic features? I don't think that would suit the eyes, but go for it if you think it will look good mate. Also, what I mean by the shading is, adding a variation of blacks on the lines, kind of like shadows, but gives the image depth. Look up "Art Shading" on youtube, google or any art website. It's a bit hard to explain, but an image might help you understand what I mean. Keep going with it man, just make sure the mouth/nose area is filled with something later, I feel it's a bit too empty. But that's just my opinion on it.