Mash is a steam engine-based life form, built by Dr. Sendagaya for his granddaughter Mina. The three of them live peacefully together until Mina is kidnapped by the evil Gash. Naturally, Mash must begin a quest to save his beloved Mina.

The games has mutliple stages, most of these are laid out in a maze-like fashion. Special weapons are required to open certain doors. The concept is similar to Nintendo's Metroid series, while the isometric view and the ability to spin around the own axis by 360° was seen in Skeleton Krew first.

The English patch was released in late 2026.