Now that you've gone and done that, I have a few more suggestions, and an edit to go along with them;
I fooled around with the colors and the shading and added some unnecessary fluff, but I circled the areas which are related to the more essential changes.
- That blueish gray on the eye is actually blending with the Goomba's skin-- my edit shows a possible alternative.
- That second shade on the Goomba's head is a tad too dark, it's blending with that brown's darkest shade. It's also much too unsaturated. The same could be said about the body's second shade, but to a much less drastic degree.
I fooled around with the colors and the shading and added some unnecessary fluff, but I circled the areas which are related to the more essential changes.
- That blueish gray on the eye is actually blending with the Goomba's skin-- my edit shows a possible alternative.
- That second shade on the Goomba's head is a tad too dark, it's blending with that brown's darkest shade. It's also much too unsaturated. The same could be said about the body's second shade, but to a much less drastic degree.