Apart from the thing meantioned below its definitely a nice sculptur using nice colors on a limited palette, thats awesome for a first submission, hope to see more of you soon.

Yeah, the AA made me think the image was compressed badly or blurred by the scaling down to the small image.

Your highlights don't define the shape of the creature very well. The way you've highlighted every right edge and shaded efery left edge makes it look kind of like a flat, embossed thing rather than a 3d beast.