In the retro-futuristic world of , the story is set in a 1940s-inspired coastal American city called Coastal City . The narrative follows a hardened biker gang known as the Steel Rats , who must defend their home against an invading army of "Junkbots"—alien-like machines made of scrap metal that have suddenly emerged to consume the city.

The story centers on four playable members of the gang, each with a unique background and motivation:

: The seasoned leader of the Steel Rats, motivated by a sense of duty to protect his territory and his "family."

: A mysterious tech-expert with a deep connection to the origins of the mechanical menace.