One day while Maru and Cori are taking a walk in Central Park, a strange thing happens. Out of nowhere this weird looking guy shows up and waylays the unsuspecting couple. Before Maru can respond, the weird looking guy and Cori vanish without a trace, leaving Maru behind wondering what in the world just happened.

Maru's Mission is a side scrolling action game. Traveling throughout the world from such locations as the USA and Romania, you fight mythological monsters such as Isis and Dracula.

Maru can shoot sparks in rapid succession and can also get access to a variety of powerful different weapons. Maru can collect hearts to replenish his health and jump to avoid obstacles or dodge enemies. Levels are usually finished by defeating a level boss which sometimes earns a new weapon.