That you mention it, it likely is the head placement that makes it look rather...odd. It looks either as if he is very hunched over or is one of those bodybuilders who stereotypically has no visible neck.
That being said, Link really isn't the bulky type. It looks as if you're portraying him as such here; I would definitely try to work on that...unless that is what you were trying to go for.
A small nitpick, but you may want a slightly darker outline color. It's pretty similar to the darkest green shade, there.
Also, his shield...it looks elliptical. Tear-shaped. Last I checked, Link's shield had a shape more like this:
Not bad so far, overall; keep on trucking!
That being said, Link really isn't the bulky type. It looks as if you're portraying him as such here; I would definitely try to work on that...unless that is what you were trying to go for.
A small nitpick, but you may want a slightly darker outline color. It's pretty similar to the darkest green shade, there.
Also, his shield...it looks elliptical. Tear-shaped. Last I checked, Link's shield had a shape more like this:
Not bad so far, overall; keep on trucking!