My goal with Gun Runner was to create a First Person Shooter that was on-rails and also featured some of the specific tropes of the Endless Runner Genre (replaying levels over and over, improving attributes each time so you make it further along, difficulty ramping up as you progress). I've decided to make it so you spent money to be allowed to 'run' for one of four factions and you have a different loyalty level with each faction, allowing you to buy different levels of boosts.