Star Ving, a planet that has many islands which are all connected together by rainbows, is the home of the Munchables, spherical, food-loving creatures with unsustainable appetites, who are all led by the mysterious "Great Elder".

A UFO then unleashes masses of "Tabemon monsters", space pirates who are trying to rule the universe, all over the islands to destroy everything in their wake.

The Great Elder decides to use this to his advantage and goes with two distinct Munchables, named Chomper and Munchy, to explore the islands of Star Ving, devour the Tabemon monsters, and retrieve all of the Legendary Orbs.

It is also revealed that the Great Elder is a Tabemon monster himself, which explains the running gag in which the playable characters constantly try to eat him.

After finally escaping from the space fleet and getting back to Star Ving, the heroes are too late as Don Onion has used all of the Legendary Orbs to create his most powerful Tabemon monster: a mechanical monstrosity called King Pumpkin.

Don Onion winds up trapped in the wreckage of the rocket, and Chomper, Munchy and the Great Elder stare into the night sky and cry as the credits roll.

The second mission always involves traveling to a certain point in the level to defeat a particularly large and powerful monster referred to as the "Leader Pirate".

The characters in the game can move, jump, and eat enemies based around foods such as fruits, vegetables, desserts, and even robots in order to grow and become stronger.

At the end of each mission, the player is scored by how many orbs their Munchable expels from their body (all depending on how much they ate) and are granted a lettered rank from "C" to "S" based on the number.