World of Light

Adventure Mode: World of Light ((灯火の星) is the single-player Adventure Mode in Super Smash Bros. Ultimate. It is the third Adventure Mode in the series, after the original Adventure Mode in Super Smash Bros. Melee and The Subspace Emissary in Super Smash Bros. Brawl. World of Light is accessed from the Spirits menu in Ultimate, and was unveiled at the end of the November 1, 2018 Nintendo Direct.

Saving fighters in this mode is how they are unlocked in the multiplayer modes of this game.

Plot
The story begins on a cliffside resembling the cliff overlooking the Isle of the Ancients at the end of The Subspace Emissary. Many of the fighters, including Samus, are seen on this cliff, observing a massive armada of Master Hands approaching them. Fox, Marth, Zelda and Pit speak briefly to consider a battle plan and reassure the fighters that they will win. Suddenly, all of the Master Hands are disintegrated and absorbed into a light being named Galeem. As the fighters prepare to attack, Shulk foresees that they will fall, and attempts to warn them to no avail. Galeem creates a black hole, which collapses and produces a thousand beams of light.

The beams of light quickly approach the fighters and consume them all. Samus attempts to fire at the beams, but is overwhelmed by one. The beams transform the fighters into Puppet Fighters and consumes the entire galaxy, turning non-playable characters into Spirits.

Kirby is the only fighter to survive the attack, thanks to the light-speed power of his Warp Star. After escaping the beams, Kirby crashes into a barren wasteland, inhabited by Spirits flying above it. Recovering, Kirby gazes out upon the World of Light, a vast landscape.

In a dark room, a gold substance is shown pouring over Mario in his trophy form. The substance pours under the base of the trophy and creates a replica, which falls to the ground with a thud. A Spirit takes over the trophy, and Mario emerges as a Puppet Fighter. The camera zooms out, and shows the other fighters have suffered the same fate.

Zero Suit Samus (who is likely amalgamated with Samus in this mode), Ridley and Dark Samus are not witnessed during the introduction cutscene, but it can be presumed that they were turned into Puppet Fighters as well.