Adventure Mode: World of Light

Adventure Mode: World of Light is a mode in Super Smash Bros. Ultimate, similar to Melee's Adventure Mode and Brawl's Adventure Mode. It was first revealed at the end of a Nintendo Direct on November 1, 2018.

Overview
On November 1, 2018, a Nintendo Direct ended with a cutscene that featured the entire roster of Super Smash Bros. characters going up against a mysterious foe known as "Galeem" with an army of Master Hands. They were all seemingly vaporized (except for Kirby who managed to escape on his Warp Star) along with the rest of the universe. Kirby then crash-landed on a mysterious planet and embarked on a mission to save everyone who are revealed to have been captured and cloned, with the help of Spirits.

First Trailer
The trailer begins with Fox leading the majority of the playable characters (both heroes and villains) against an incoming army of Master Hands (with Marth claiming that the Hands outnumber them 10 to 1). Before the battle begins, the Master Hands are absorbed by a mysterious being known as Galeem.

Galeem uses its powers to create beams of light that decimate every fighter they hit; regardless of their agility, power or defenses. Kirby is the only exception and manages to flee on his Warp Star. Galeem's magical light then quickly engulfs the world and eventually the entire universe.

Then, Kirby wakes up on a mysterious planet and begins his journey to rescue his friends who are revealed to have been captured by Galeem who used a magical liquid metal to create evil clones of every character.