Mixed feelings about this game.
It looks great, very atmospheric, the voice acting is good, the missions and mini-games seem very much in keeping with the feel of the era. I really like too the way several elements of the game seem taken right out of various Western movies. The band of criminals holed up in a deep, twisty gorge. The shoot-out on a rocky out-crop with you ducking between the boulders. The dodgy snake-oil merchant..
The controls feel a little awkward for me though - in particular when on horse-back. There are a few spots (especially on slopes) where you can get stuck, and it's amusing watching your horse moon-walking around trying to get out. And it's far too easy to fall off a ledge or into water (instant death).
One annoyance, on some missions you're asked to bring a criminal back alive, but if you haven't done a certain mission where you learn to lasso, you have no way of doing so. I spent ages trying to cripple/knock a guy out, only to eventually realise I had to kill him.
Another oddity - sometimes you fight your way through a location as part of a mission, only to have to go back and fight through it again as part of a 'freeplay'. Odd.
For a free-roaming game though, there doesn't seem to be much 'need' to explore. There are side-missions, though some of them are very brief and many of them repetitive. Most of the interesting gameplay comes from the main missions, all of which seem centred around the same town.
Still, it's really growing on me the more I play it.
p.s. I did notice one funny bug though. I was fighting my way through Tumbleweed. I went to crouch down by the well in the centre of town, and was suddenly thrown waaaay into the air above the town. Needless to say, my character didn't survive the landing.