I don't know why, but the buildings in the background remind me of Team Fortress 2. I like the dust effects, it makes it look more like the Wild West than just some re-enactment of the stereotypical cowboy-vs-cowboy shoot-out that you see at historical town museums. One thing I think it may be missing though is a bullet casing being expelled from the gun. And a bit of a trim on that left hand. But this looks really cool still. Good job.
(I love the character and pic, but that one claw/hand bothers me.}