i think the top half of the character is fairly ok, but the hips need to be quite a bit wider i think. i like the bark effect on the branches. good shading though on the character. hands are very well done compared to everything else.
obviously it depends on the style of clothing, but i think the horizontal part of the neck line of the top should be more straight, as if it is stretched between the breasts more, otherwise it looks loose. that may have been the intention though. its a very minor thing though :P
maybe the moon would look nice with a bit of texture?
but good use of tones from fully black to fully white, its very balanced.