You have some great details on the dragon itself, but I think that the background is taking away from it. it's too bright, and its large areas of color kinda distract from the main piece. I would, based on the dragon itself, also expect them to be a bit more tightly pixeled. The head might could also use some more definition at the top to distinguish it from the backgroun.
Anyway, there's some truly awesome pixeling here; it just needs to be brought out a bit more, I think.