I like it, but I think it needs a bit of cleaning up to really bring out the details.
When you're working on something this size, I think it's important to make the most out of the little space you have, and use thin outlines if you're going to use any. Another thing that adds to line thickness is the color of the lines. High contrast lines seem thicker, so try to avoid using black where it's not really necessary in order to see the lines.
Dithering should also be used with care, preferably only to blend colors where needed and suggest texture (scales in this case). You also have a bit of banding and some similar colors. I think it's a good idea to keep the increase/decrease in hue/saturation/brightness fairly constant between the colors in the ramps, but also keep in mind that you need fewer colors in ramps that are only going to be used in small areas (like the white) than in the colors for larger areas (like the red). Your palette is also a bit plain at the moment. Try varying the hues a bit more.
The dragon itself seems to lack a clearly defined light source. Try to move the highlights closer to the light and add more shadow in the other end. You can use ambient light to suggest forms in the darkest parts if you feel you lose too much detail by doing that.
The shadow cast by the dragon on the ground could be lighter so it's easy to tell it apart from the dragon itself.
This is a fairly extensive edit, but I wanted to give you some ideas for colors and how to sharpen it up a bit and still keep it AAed and dithered. I thought green would serve as a nice contrast to the red and moved the highlights towards yellow. You're free to find other combinations, of course.
I hope that's useful.
