The Adventure Mode: World of Light is casually called World of Light. It is an adventure mode found in Super Smash Bros. Ultimate. The story is about a god-like being named "Galeem" (Kīra in the Asianic versions of the game) who has gone rouge. It unleashes inescapable beams of light and death, horiffically murdering all the fighters reagrdless of their power, agility, or defense. Kirby warps on his warp star to saftey. Galeem then kills the whole galaxy to the point where there's NOTHING LEFT. Once his work is done, Galeem creates puppet fighters of those who fell victim to his powers. Once Kirby crash lands, he sets out to save all who fell victim to the unholy god, not realizing that there's also a darker counterpart of Galeem.
At the start of the game, Galeem and his army of Master Hand clones are closing in. Fox McCloud aims his blaster in their direction, telling his friends not to let a single one get away. Marth remarks that the heroes would need to each take down 10. Princess Zelda then requests that Marth stows his fear, and that it is now or never. Pit then shows optimism as he says that the Smashers will win their next fight.
However, Shulk sees that Galeem had laid a trap in their way. The Master Hands disintegrate and Galeem becomes a black orb that draws their energy in. Just after his transformation, Galeem erupts, destroying nearly everyone, but Kirby escapes on a Warp Star.
Kirby crash lands as Galeem uses his victims to create Puppet Fighters. These Puppet Fighters then spread out to hunt more of their basis's ilk.
Eventually, Kirby frees the heroes and the gang sets out to face Galeem. However, once they beat him, a Black Hole tears open in the sky.
Dharkon (Darz in the Asianic versions) comes from the hole to seize his opportunity to rise to power. Galeem, knowing that his current form cannot match Dharkon's power, retreats. Dharkon captures some of Galeem's puppet fighters and creates a dark dimension. Just as what happened to Galeem prior, Dharkon himself is defeated and retreats for his own safety. Galeem, having regained some of his power, returns. He follows the demonic entity through the portal, which leads to a chaotic realm.
The two gods fight as the heroes pop in. Dharkon turns his eye in their direction as Galeem just flashes in ire. The heroes free and round up the remaining fighters who were captured, and the final battle begins. Eventually, Galeem and Dharkon are defeated. Their remains plummet into the sea before the two gods explode, restoring order. The Smashers rebuild in the new world.
- Molten Fortress: a sub-area that has spirits that are affiliated with fire or lava. Molten Fortress is based off the final level or Bowser's Castle from the Mario franchise. There are two captured fighters, Peach and Bowser. Hence the locations where Peach and Bowser are found, it references Peach's usual damsel-in-distress role.
- There are Puppet Fighters of Kirby, although he has not been caught by Galeem. Later, Masahiro Sakurai has explained that Galeem analyzed Kirby without capturing him.