Take a look at the co-op gameplay for Guns of Eschaton, a Soulslike FPS set in an occult Wild West and created by the late, legendary writer and worldbuilder Viktor Antonov (Half-Life 2, Dishonored, Prey, Fallout 4, and Wolfenstein: The New Order).
This isn't a fast-paced shooter where lightning-fast reflexes guarantee victory. Every bullet counts. Every weapon has its own personality. Every enemy has a weakness waiting to be exploited.
Choose your ammunition carefully for each chamber of your revolver, study enemy weaknesses, and adapt your approach using specialized bullet types, perfectly timed parries and dashes, and mystical abilities granted through the occult.