Octopus

Octopus, known as Mysteries of the Sea and Mysteries of the Deep in the United Kingdom, is a Game & Watch game released as part of the Wide Screen series on July 16, 1981. In this game, the player must get as much gold as they can. However, they must watch out for the Octopus near the treasure because if they touch its arms, they lose a life. Losing all three lives results in a Game Over. Octopus also appears as a minigame in Game & Watch Gallery, Game & Watch Gallery 4, and Game & Watch Collection 2. Also, in Game & Watch Collection 2, there is a game titled Parachute x Octopus that combines Octopus with another Game & Watch game, Parachute.

The alarm indicator of this game is a young octopus that is located beside the time/score, and the young octopus sounds a trumpet when the alarm goes off.

Classic version
Three scuba divers head for a treasure chest under the sea, guarded by the Octopus. The divers must be patient because the Octopus's arms are moving randomly. The player earns one point for every piece of treasure they grab and three points for returning the load to the boat. As the player progresses in the game, the Octopus's arms will move faster. Game B is faster and more difficult. All three lives are restored once the player hits 200 and 500 points.

Modern version
The gameplay in this version is largely the same, but the graphics are updated, and the divers are replaced by Mario down below and Princess Peach in the boat. In this version, Mario earns twice as many points for every piece of treasure he brings to Peach. However, Mario gets slower as he grabs more treasure. To counter this, he can throw all of his treasure, which lightens his load and can stun one of the Octopus's arms for a brief time. Sometimes the Octopus squirts clouds of black ink, and if one hits Mario, he receives a miss. When Mario amasses 200, 500, and 700 points, a Lakitu will appear and drop a heart for him to remove a miss. The Modern version also features music, with the tempo changing depending on the speed of the game. In Game & Watch Gallery 4, the Octopus changes color each time the player gets 200 points.

In Game & Watch Gallery 4, if the player selects the game yet does not actually start it, a humorous sequence is shown. Mario arrives with a bag of loot in one hand and a Game Boy Advance in another. However, he ends up surrounded by four octopus arms (two on each side) that are menacing him. Trapped, he then calls on a Lakitu to help him. He then grabs the fishing pole of Lakitu and, trying to hold on, is ultimately forced to drop his belongings, with a crown and gold objects falling out of the loot bag. Finally, each octopus arm retrieves a treasure, including the loot bag itself as well as the GBA.

Classic version

 * (up and left): Return
 * (down and right) and : Advance/Pick up

Modern version

 * (up and left): Return
 * (down and right) and : Advance/Pick up
 * Throw

Classic version

 * (up and left): Return
 * (down and right) and : Forward/Pick up

Modern version

 * (up and left): Return
 * (down and right) and : Forward/Pick up
 * Discard

References in later games

 * WarioWare: Smooth Moves: The microgame Game & Watch Octopus is based on Octopus.
 * Super Smash Bros. series: When Mr. Game & Watch breaks open the Smash Ball, he transforms into an Octopus for his Final Smash. The Octopus is also a spirit in Super Smash Bros. Ultimate. Mr. Game & Watch's up smash attack in the series involves him wearing a diver's helmet as he performs a headbutt.
 * Nintendo Land: The attraction Octopus Dance is themed after the Game & Watch game.