Some suggestions

It looks okay, but it could use some work. For example, some body parts are disproportionate- neck is too big, the upper body should be slimmer, the shield should be larger, etc. Some colors simply don't look right especially for the skin. While the background looks fine, it doesn't match the style of the character enough (character is drawn in flash and background not). Shading is technically good in that it matches the source of the lighting which is behind the character, but there should be a greater contrast in colors (the darker colors should be darker and lighter should be even lighter). The outline is too jagged, and there should be a larger color palette overall.

I hope that I'm not being too critical, but this should help improve your work.