The most basic requirement is unlocking the entire cast. While the "Everyone is Here!" tagline implies they are in the game, you start with just the original eight fighters from 1999 (Mario, Donkey Kong, Link, Samus, Yoshi, Kirby, Fox, and Pikachu).
One important note: A from version 3.0 is not 100% on version 13.0. Every time Sora, Pyra/Mythra, or Sephiroth was added, the bar for 100% moved. Super Smash Bros Ultimate 100 Save
For many players, Super Smash Bros. Ultimate is the pinnacle of fighting games. With a roster of 89 fighters (including DLC), over 100 stages, nearly 1,300 Spirits, and countless music tracks, it is a celebration of gaming history. However, for all its glory, the game has one notorious downside: The most basic requirement is unlocking the entire cast