The game stars two snakes, Rattle and Roll, who must eat small, spherical creatures called Nibbley-Pibbleys as they climb a mountain in a "race to the moon". As the two snakes eat the Nibbley-Pibbleys, they grow in length and weight, allowing them to tip a scale, opening the door to the next level. The game is considered one of the most challenging to have been released for the NES. This unusual difficulty sets in during the game's early stages, likely hampering its appeal for casual and novice players. It is notable for being one of the earliest platform games to use a 3D isometric playing field. Despite it's innovation, the game sold poorly and remains relatively obscure, possibly a result of its high difficulty level and unintuitive controls.