General character changes:
- Characters that had infinite jabs now have a finishing move.
- There's a customization feature that allows changing the characters' special moves. It can't be used online against strangers, being available on local multiplayer and online multiplayer with friends.
Mario:
- FLUDD has a seemingly longer range.
- Customization allows his Fireball move to have new variations: a big, but slow projectile or rapid fire projectiles with a straight line trajectory.
- His Super Jump Punch can be customized to feature fire.
- New moves via customization: Fast Fireball (Neutral Special), Fire Orb (Neutral Special), Gust Cape (Side Special), Shocking Cape (Side Special), Super Jump (Up Special), Explosive Punch (Up Special), High-Pressure F.L.U.D.D. (Down Special), Scalding F.L.U.D.D. (Down Special)
Luigi:
- New Final Smash: Poltergust 5000. It sucks other characters in the vacuum and launches them afterwards.
- Has a new paddling animation for his jumps taken from the Mario series. Seems to lower his falling speed.
Peach:
- Her Up Smash features a spiraling ribbon, seemingly giving the move a larger hitbox.
Bowser:
- Has a new, upright stance and new moves.
- Has a new running animation and is faster doing so.
Donkey Kong:
- Has a new dash attack in which he performs a rolling attack from the Donkey Kong Country series.
- Through customization, his Headbutt can be made to give him super armor, but the move's speed is decreased.
- New Special Moves via customization: Giant Blow (Up Special)
- He can now use his Hand Slap move on the air.
Diddy Kong:
- The Peanut Popgun's explosion due to excessive charge now causes damage.
- He possesses more flexibility, giving his moves bigger range.
Link:
- His down aerial attack is now a Meteor Smash, though it's subject to change during development.
- He now has the jump attack from the Zelda series. Seems to be his new dash attack.
- His tether recovery has a longer range.
- Through customization, he can use the normal Boomerang instead of Gale Boomerang like in the original Smash or in Melee.
- His Final Smash, Triforce Slash, is faster.
Zelda:
- New Down Special Move: Phantom Slash. Zelda summons a Phantom from The Legend of Zelda: Spirit Tracks who charges forward and slashes with its sword. The move is chargeable, which determines how far the Phantom goes. The Phantom is also treated like a projectile, being able to be reflected or picked up by the Villager. It can also be used to block the foes' attacks.
- As a result of having the new move mentioned above, she can no longer transform into Sheik during battle.
- Her Final Smash, Light Arrow, is faster.
Sheik:
- New Side Special Move: Burst Grenade. Sheik throws an explosive projectile at the foes.
- New Down Special Move: Bouncing Fish. An acrobatic kicking move.
- Can no longer transform into Zelda during battle.
- Has a new tilt move.
- Up aerial now deals multiple hits.
Toon Link:
- The taunt where he looks around now features a fairy.
Samus:
- Has a new look based on Metroid: Other M.
- Her Forward Smash now produces an explosion, having a bigger hitbox.
- Her Final Smash, Zero Laser, no longer destroys her Power Suit, meaning she no longer switches to Zero Suit Samus during battle.
- Her tether recovery has a longer range.
- New Special Moves through customization: Melee Charge Shot (Up Special)
Zero Suit Samus:
- Can no longer switch to Samus during battle.
- Was given new jet boots that improve her kicking moves.
- She appears to have a new recovery move involving the jet boots.
- Has a new Final Smash. She boards her ship and fires lasers at the stage. Those can be aimed.
- Has a new entrance animation where she drops from her ship.
Yoshi:
- Has a new stance.
- His eggs' spots color matches Yoshi's selected color swap, as opposed to always being green.
Kirby:
- His Thwomp transformation done by the Stone special move was updated to look like how Thwomps look in the latest Mario games.
- New Final Smash: Ultra Sword.
- His Side Special Move was renamed to Hammer Flip and can now be charged.
- Via customization, his Inhale move can be switched to a ice breath move.
- New Special Moves via customization: Hammer Bash (Down Special)
King Dedede:
- His Waddle Dee Throw move was reworked so now he now only throws Gordos.
Fox:
- New Special Moves via customization: Charge Blaster (Up Special)
- Fox Illusion no longer renders him helpless.
- Slower recovery when landing from using the neutral Special Move.
Pikachu:
- His Thunder move is now a Meteor Smash when hitting with the thundercloud. The lightning bolt itself is also a Meteor Smash.
Charizard:
- Is now a standalone character.
- New Final Smash: Mega Charizard X.
- New Side Special Move: Flare Blitz. A charging attack that causes recoil damage to the use.
- Rock Smash is a Down Special Move.
Lucario:
- His aura mechanic is now stronger.
- Has access to his Mega Evolution, Mega Lucario, through unknown methods. In this form, his aura is maximized.
Marth:
- Has a new look based on Fire Emblem: Shin Monshō no Nazo ~Hikari to Kage no Eiyū~.
- His Shield Breaker is stronger.
- Through customization, his Shield Breaker can be altered so Marth dashes while he stabs.
Ike:
- Has a new design based on Fire Emblem: Radiant Dawn.
Pit:
- New Side Special Move: Upperdash Arm. Pit attacks using the Upperdash Arm from Kid Icarus: Uprising with an upwards blow.
- New Down Special Move: Guardian Orbitars.
- New Up Special Move: Power of Flight. A new recovery move in which Pit flies towards a certain direction.
- New Final Smash: Three Sacred Treasures.
- His gliding ability is gone, though his attacks are stronger now as a compensation.
- Through customization, his arrows can be made slower but easier to control.
- New forward aerial attack. A spinning move using his bow.
Olimar:
- Can now only carry up to 3 Pikmin at once.
- He now plucks Pikmin on a fixed order: red, yellow, blue, white and purple before repeating.
- New Up Special Move: Winged Pikmin. Calls two Winged Pikmin that carry him and his Pikmin. The more Pikmin Olimar has, the heavier the weight and the less efficient the move is.
- The Pikmin can now carry items for Olimar.
Sonic:
- Sonic's down aerial attack has a Meteor Smash sweetspot.
- Has a new down Smash attack.