Niiice! I do like the shading. I agree that the background could be a different color. Also, you could probably take out the shadow across his skirt, I know it wouldn't be totally accurate but cutting across there feels weird.
You're getting better at lineless artwork. This image is really neat and clean. I like the shading you've done on this one. I cant help but wonder if the background should me another color though. But it's looking good so far
You can use contrasting colors to make him pop, but since Link is the only thing on the poster its not necessary. You can use analogous colors too if you want to stick to a cool color scheme, like magenta or teal. Experiment, and you're welcome!