Though there isn't much here that you haven't seen before in a western revenge drama, it's pretty well done. You can understand why the protagonist turns away at any chance of a normal life and instead concentrates on nothing but revenge. And it is undeniably satisfying to see him enact his revenge any chance he gets.
It's good for what it is, though there are some problems, that if tweaked, could have made the movie even better. For one thing, casting McQueen as a half-Indian? And casting this mid-30s actor as a character that's supposed to be young enough to be called "Kid"!?!? Plus, the escape from the swamp doesn't seem finished; in fact, with the short sequence where one of McQueen's pursuers commenting on the bullets he has left makes me believe that several minutes were edited out before the movie was released.