The plastic feeling could be remedied easily by diversifying your highlights more. Currently they are all too similiar. The high contrast also contributes to the plastic feel, try adding some folds and perhaps remove the higlights that are on the lower part of the coat, the thighs, and the top part of the boot. That will help give your sprite more volume as well.
I should mention your palette is very cool though; and I was able to see your image when it was posted initially, I'm curious what the previous posters were viewing with? (I'm using firefox) I heard that netscape sometimes has trouble viewing certain images as well as pcs with parental controls.