The level follows the events of the Battleship Halberd Interior and the Battleship Halberd Exterior. The group consisting of Snake, Meta Knight, and Lucario fight their way through enemies of the Subspace Army until they reach the Battleship Halberd's bridge. Here, five Shadow Bug copies of Mr. Game & Watch (the only time in which a hero doesn't have its name shown when introduced) are seen piloting the ship. Snake charges and knocks them all off the bridge and onto the deck below, disturbing the tea party of Fox, Peach, and Sheik. As the clones make contact with the deck, they revert to Shadow Bugs, which all join together to form the huge machine, Duon. Fox, Peach, and Sheik get up to fight it, and are joined by Snake and Lucario from the Bridge. Meta Knight stays on the bridge to fly the ship. A last minute addition to the team is Falco, who ejects from his Arwing to land on the deck. After Duon is defeated, the Shadow Bugs dissolve to reveal a Trophy of Mr. Game & Watch. Fox aims his Blaster at it, but Peach walks past Fox smiling. She then revives Mr. Game & Watch. The confused Mr. Game & Watch tries to understand what is happening but remains puzzled. To cheer him up, Peach gives him her Parasol to play with, which enthralls Mr. Game & Watch. Meta Knight walks on the Halberd until he reaches the ship's steering wheel, in which, he turns to the left. The Battleship Halberd turns left and escapes out of the red clouds, and into the Isle of the Ancients. After that, Mr. Game & Watch will join the player's team.
When the player begins, he will be sent to a boss battle against Duon. Items will fall to help the player defeat Duon. Duon loses health very slowly, which makes the battle longer. He has two sides: the pink side attacks with missiles, and the blue side attacks with sword attack. After Duon is defeated, the level is complete and Mr. Game & Watch will join the player's team.
- The boss battle music is- Boss Battle Theme 1.