So I came across this game the other day after seeing it mentioned in an article, the fact that it was a western setting piqued my interest.
The game started out as a free browser game: Westerado but there's now a purchasable version on Steam called Westerado: Double Barrelled which has improved graphics and extra content to flesh out the game.
Here are my thoughts on the free version (I'm keen to pick up the paid version at some stage) The core aspect of the game is that you're hunting down the person who killed your mother and burned down your farm. The trick is each time you play the game the identifiable characteristic of the killer are randomly set. You gather clues as to how the killer looks by performing jobs as a gunslinger for the people in the area, each time getting a bit more information such as what type of hat he wears, if he is fat, the colour of his pants etc.
The cool thing is that you can go about finding the killer however you want. You can also pull your gun on any person you meet and accuse them of being the killer - you can shoot anyone you want too (including questgiver NPC's) and so change how the game plays out each time. It's incredibly satisfying when you finally find the killer - but have to ask yourself was is worth all you did in getting to him to have your revenge.
The pixel graphics are also really well done and set the scene well.
Give the free version a try - this game is certainly a lesser known gem.