He looks good for a fan art of link. Yeah, a reference of link would help lots . I think he looks flat because of the clothes. I suggest redoing the whole thing lol. Good luck . 

Did some tweaking myself. Yeah I agree with Johnathan with the hammer there, looks like a flat piece of wood with a hammer shape to it. I added depth to it, as you can see from here. I've also made shadows for the shadows of your swords too. Don't be afraid to make shadows for the shadows. Especially for cubes, polygons, etc. Overall, very nice sprites you have done for such a small project like this. I am impressed .

 Here's my example:

 

Looks good for starting out your bgs . You should remove the black outlines. They are good for seperating one part for each other, yet they aren't suitable for bgs. Use a dark color of the base color's to outline it.

Heh, I like it! You don't need the dithering for the clothes there man. The dithering just makes the clothes look grainy. You can use folds instead like I did with the shirt.

 I think it looks like you started with a silhouette, if I am wrong. You should start the piece by drawing an outline first and work your way how you want it. In my pixeling experience, you need foundation. Once you have the foundation down, you can pixel it to your taste. Use the outline as foundation at all times, it's a great friend to anyone .

 Next, I've darkened the darkest shade you got there so it doesn't resemble the other shade. Don't actually make shades look similiar to each other, it will actually make it look too blurry.

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