It isn't that bad compared to some stuff I've seen in Pixel Art. But still, there is room for improvement. First of all, the transition from the jacket to the head is a bit odd. You could use some neck in there because otherwise it looks like he's wearing a turtleneck, which I don't think is what you were going for. You could also maybe try to add a collar or something else like that up at the top, to make him look cooler.
Next, there is the shading. The shaded areas need to be darker in contrast with the lighter areas. Also, what's up with the series of dots running down the jacket on the sides? Are those supposed to be buttons? If so, then they should be in a different color, like black, and only appear on one side. If not, then they have no reason to be there.
Last, there are two minor issues. a) The legs should be slightly longer, and b) the hand on the left looks a bit odd.
Its still a lot better sprite than a lot out there, like I've said. Just fix these things and you'll be all set. :)