Fantastic usage of style and color here. The negative space thanks to the void of white complements your palette very well. I adore the little triangle of blue in the bottom left, I think that works -so- well in bringing this image together.

I find the sand to be distracting, though. It looks as if you started to draw it normally, then took the smudge tool and wiggled it around until there were no traces of your linework left. I find your lines to be quite lovely, and wish that they continued into the sand, instead of turning into a weird sand-colored blob.

Sidenote, I would like to read The Sandman at some point, heard so many good things.