The Subspace Emissary is a single-player adventure mode featured in the video game Super Smash Bros. Brawl. It combines platforming elements with traditional fighting mechanics, allowing players to control various characters from the Super Smash Bros. universe as they navigate through different stages and defeat enemies. The mode includes a storyline that connects the characters and their battles. Throughout the Subspace Emissary, players encounter familiar characters such as Mario, Link, and Pikachu, as well as new foes like the Subspace Army. The mode emphasizes teamwork, as players can unlock and team up with different characters to progress through the game.