Extreme Labyrinth

Extreme Labyrinth is the Adventure Mode for Super Smash Bros. Extreme. It takes elements from Brawl's Subspace Emissary and Ultimate's World of Light.

Opening
The opening starts with every fighter in the game on a platform in a large cavern. The fighters are looking up at Master Hand, Crazy Hand, and Labrain. All of the fighters charge up their attacks. But then Master Hand and Crazy Hand create a force field attack that knocks away all of the fighters, leaving them scattered in the labyrinth.

Gameplay
There are 8 different areas in Extreme Labyrinth, each containing levels. Every level ends with a shadow version of a fighter. By defeating the stage, you unlock said fighter. Every fighter in the game has one except Mario and Kirby, whom you start with.

When you defeat every stage in an area, that area's boss will appear. Beating all 8 bosses unlocks the final boss.

You can only use each fighter in their respective areas. Only Mario and Kirby can be used in any area. After beating the final boss, you can use any fighter in any area. Stages can be completed in any order regardless of area.

Grasslands
Boss: Boom Boom (Mario)
 * Luigi
 * Peach
 * Daisy
 * Wario
 * Sonic
 * Villager
 * Shulk
 * Duck Hunt
 * Cloud
 * Isabelle
 * Lloyd
 * Paper Mario
 * Banjo-Kazooie
 * Bandana Dee
 * Mach Rider
 * Rayman
 * Erdrick
 * Toad
 * Rex
 * Venusaur
 * Isaac
 * Elma

Forest
Boss: Vehemoth Phosbat (Pikmin)
 * Donkey Kong
 * Link
 * Yoshi
 * Jigglypuff
 * Diddy Kong
 * Olimar
 * Toon Link
 * Greninja
 * King K. Rool
 * Dixie Kong
 * Geno

Ruins
Boss: Elder Grex (Xenoblade Chronicles)
 * Sheik
 * Zelda
 * Marth
 * Pit
 * Ike
 * Palutena
 * Robin
 * Alm
 * Anna

Laboratory
Boss: Kraken (Golden Sun)
 * Samus
 * Pikachu
 * Zero Suit Samus
 * R.O.B.
 * Mega Man
 * Ridley
 * Bomberman
 * Sylux

Mountains
Boss: Kracko (Kirby)
 * Ice Climbers
 * Meta Knight
 * King Dedede
 * Lucario
 * Corrin
 * Simon
 * Skull Kid
 * Hector

City
Boss: DJ Octavio (Splatoon)
 * Ness
 * Mr. Game & Watch
 * Lucas
 * Wii Fit Trainer
 * Little Mac
 * Pac-Man
 * Inkling
 * Joker
 * Spring Man
 * Balloon Fighter
 * Chorus Men
 * Phoenix

Stratosphere
Boss: Necrozma (Pokemon)
 * Fox
 * Falco
 * Mewtwo
 * Wolf
 * Rosalina
 * Marshadow
 * Leon

Volcano
Boss: Pom Pom (Mario)
 * Bowser
 * Ganondorf
 * Roy
 * Bowser Jr.
 * Ryu
 * Bayonetta
 * Incineroar
 * Black Shadow

Smashing Split Phase
After every level and boss level is completed in all 8 areas, a new level will appear. This level activates a cutscene that starts out almost identical to the opening cutscene of Extreme Labyrinth, with every fighter in the game in a cavern with Labrain and the two hands. However, this time, Master Hand and Crazy Hand don't create a force field. Instead Labrian charges up energy, then Master Hand and Crazy Hand snap their fingers in unison. This unleashes an attack named "Smashing Split" which instantly kills off half the characters.

Survivors

 * 1) Mario
 * 2) Donkey Kong
 * 3) Link
 * 4) Samus
 * 5) Yoshi
 * 6) Kirby
 * 7) Fox
 * 8) Pikachu
 * 9) Luigi
 * 10) Ness
 * 11) Captain Falcon
 * 12) Jigglypuff
 * 13) Daisy
 * 14) Zelda
 * 15) Ganondorf
 * 16) Roy
 * 17) Mr. Game & Watch
 * 18) Zero Suit Samus
 * 19) Ike
 * 20) Lucas
 * 21) King Dedede
 * 22) Lucario
 * 23) Wolf
 * 24) Mega Man
 * 25) Pac-Man
 * 26) Bowser Jr.
 * 27) Ryu
 * 28) Ridley
 * 29) Simon
 * 30) King K. Rool
 * 31) Incineroar
 * 32) Banjo-Kazooie
 * 33) Mach Rider
 * 34) Skull Kid
 * 35) Bandana Dee
 * 36) Anna
 * 37) Isaac
 * 38) Black Shadow
 * 39) Hector
 * 40) Marshadow
 * 41) Bomberman
 * 42) Chorus Men
 * 43) Geno
 * 44) Elma
 * 45) Phoenix

Killed Off

 * 1) Peach
 * 2) Bowser
 * 3) Ice Climbers
 * 4) Sheik
 * 5) Falco
 * 6) Marth
 * 7) Mewtwo
 * 8) Meta Knight
 * 9) Pit
 * 10) Wario
 * 11) Diddy Kong
 * 12) Sonic
 * 13) Olimar
 * 14) R.O.B.
 * 15) Toon Link
 * 16) Villager
 * 17) Wii Fit Trainer
 * 18) Rosalina
 * 19) Little Mac
 * 20) Greninja
 * 21) Palutena
 * 22) Robin
 * 23) Shulk
 * 24) Duck Hunt
 * 25) Cloud
 * 26) Corrin
 * 27) Bayonetta
 * 28) Inkling
 * 29) Isabelle
 * 30) Joker
 * 31) Spring Man
 * 32) Lloyd
 * 33) Paper Mario
 * 34) Alm
 * 35) Balloon Fighter
 * 36) Ghirahim
 * 37) Rayman
 * 38) Agnes
 * 39) Toad
 * 40) Rex
 * 41) Venusaur
 * 42) Dixie Kong
 * 43) Sylux
 * 44) Impa
 * 45) Leon