The story of The Lost Vikings revolves around four kidnapped Vikings: Eric the Swift, Olaf the Stout, Baleog the Fierce, who are being held captive by an alien named Tomator. Tomator is a Croutonian ruler who has been collecting unique life forms to display in his gallery. The three Viking brothers must use their unique skills to defeat Tomator and his minions, including aliens, robots, giant snails, and big lizards.
The gameplay of The Lost Vikings is action-packed and puzzle-filled. Players control one Viking at a time, but can switch between the three characters at any point. Each Viking has their own skills: Eric can jump and run, Olaf has a shield that can block attacks and function as an air glider, and Baleog can shoot arrows or wield a sword. The player must use the Vikings' abilities in combination to progress through the levels and overcome obstacles.
The game features side-scrolling platform elements, with players needing to navigate the Viking through increasingly difficult terrain. Each Viking has three health points, and if all of these are lost, the Viking dies, forcing the player to restart from a previous checkpoint. The Vikings also have limited inventory space, which can be used to collect items and solve puzzles.