Kinzie has birthday and the whole Saints Row crew celebrates! Matt brought a Ouija board, but unfortunately it calls Satan and drags the Boss into Hell. Gat and Kinzie follow them to rescue their leader. There they'll meet old acquaintances (e.g. Dane Vogel and Dex) and historical figures (e.g. Shakespeare and Blackbeard).
Saints Row: Gat out of Hell is an add-on sized successor to Saints Row IV. The main difference to the main game is the lack of story missions - the plot progresses by doing enough side missions. When enough chaos is created, a cutscene starts and a new side mission type gets unlocked. After the third cutscene, the player is ready to face the end boss. Other major differences are the city (Hell is new, but smaller in scope than Steelport), the lack of customization (the player either controls Gat or Kinzie) and no licensed music.
Character development is identical to Saints Row IV except that new super powers are unlocked by finding and activating altars and flying works a bit different: Kinzie/Gat don't hover like Superman, but have giant wings. This causes them to slow down over time until they flap. They start with one flap per flight, but this number can be upgraded. While most distractions are known from the predecessor (but re-designed to fit the scenario), a few of them are new, e.g. shutting down factories by fighting over three control points. The four available activities are hellblazing (a flying checkpoint race), torment fraud (a insurance fraud variant), mayhem (causing chaos with a given weapon/vehicle) and salvation (husks fall from the sky and have to be collected by the flying player before they reach the ground).