The game's instruction manual features an extensive backstory for Gex, who lived in Maui with his mother and siblings, whilst his father was working at NASA. Due to an incident involving a band-aid floating in a fuel tank, Gex's father was killed, causing Gex to become a shut-in, sitting and watching TV all day.

After moving to California and his mother selling the TV away, Gex runs away from home and sleeps in the garage of a local punk he befriends. At his deteriorated state, Gex imagines an invisible friend known as "The Mayor." With another death in the family, this time being Gex's Uncle Charlie who was the original model for the Izod shirt logo, this leaves Gex's family with an inherited fortune of 20 billion dollars.

With his share of the money, Gex leaves his family behind, returns to Maui, and purchases a mansion with the largest TV set in the world and enough food to last him for decades, so that he'll never have to leave the television again.