Gunslinger is the fourth installment of the Call of Juarez series of western-inspired games. The frame story, told in cutscenes, begins in 1910, in Kansas, where Silas, a patron in the pub, brags about his adventures in the Wild West. This old man claims he used to be a bounty hunter who took down many of the famous outlaws. Most of the game has the player re-enacting Silas's presumed past, while in the present the hero is narrating his own story off-screen. Silas is an unreliable narrator, however, and his own in-game audience will point at plot holes in his tall tales.

Like the rest of Call of Juarez games, Gunslinger has every classic staple of the western genre. There are saloons and gold mines, stagecoaches, Indians and cowboys, sheriffs and gangs. The protagonist will escape prison, wander the Wild West, fight brigands and other enemies using a variety of late XIX century firearms, and occasionally sing country songs. Gunfights and duels are the central features of the game. There's even a Duel mode, in which the player can enter a tournament of gun duels, and the Arcade mode, in which multiple opponents attack the player. Gunslinger also introduces quick time events that allow the player to evade bullets.