Nice attempt but there are some noticeable problems with it. Contrast between some of the colors could use work, the eyes feel a bit too big and are filled with jaggies. The cracks on the top of the head feel very rough, very unnatural, when creating cracks and the such you should probably use more reference. There is a bit of pancake shading on the smoke and the smoke feels way too solid(unless its not smoke, if its not smoke than the readability can use some work. On that subject the pink figure in the bottom middle has low readability and so does the figure on the far left, you should try to see if you cant make it more apparant what they are next time around. The lips feel very rough in shape as well, and the bottom lip can use more shading underneath it, right now the bottom lip feels almost flat against the face because the curve that lowers the lip into to the chin should be more apparant. The hand to the right suffers a similar situation to the smoke where it has smome banding/pancake shading that could use more shape too it. The right side of the face could be anti-alaised into the background to make it feel overall smoother. Good job on the dithering! You could definitely use more practice with dithering but you did it better than a most others who are near your skill level.