what colors did you use for the skin, cause in the pic I can't tell if it's brown or black.
Whatever color you want the skin to be (red, brown, purple, etc.), paint it the brightest shade of that color they have, then use Devlan Mud wash to darken it and give it shading. Right now, there's not much detail visible in the flesh.
You did a good job on the carapace, but I think the highlights might be a little too subtle. It could just be the picture though.
Same thing for the eyes and teeth. I can't tell if it's the picture, but i looks like you didn't paint them or painted them a dark color.
Try taking pics of the mini with a dark solid background instead of white. White causes the 'auto' to close the aperture to compensate for all the "light", causing your model to look darker than it actually is.