Games like All At Once
Games like All At Once include Celeste, Webbed, SANABI, Sonic Origins, and FEZ. We matched them by the tags players give All At Once on Steam (Casual, 2D Platformer, Adventure, Pixel Graphics, and Runner): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Pixel Graphics · 2D Platformer · Platformer

Webbed
Shared: 2D Platformer · Pixel Graphics · Puzzle Platformer

SANABI
Shared: Pixel Graphics · 2D Platformer · Adventure

Sonic Origins
Shared: 2D Platformer · Adventure · Pixel Graphics

FEZ
Shared: Pixel Graphics · Platformer · Casual

Shovel Knight: Treasure Trove
Shared: Pixel Graphics · Platformer · Adventure

Owlboy
Shared: Adventure · Pixel Graphics · Platformer

Super Meat Boy
Shared: 2D Platformer · Platformer · Pixel Graphics

Montaro
Shared: Casual · Pixel Graphics · Runner

Out There Somewhere
Shared: Pixel Graphics · Adventure · Platformer

CATO: Buttered Cat
Shared: Adventure · Puzzle Platformer · Pixel Graphics

Pizza Tower
Shared: 2D Platformer · Pixel Graphics · Platformer

DAVE THE DIVER
Shared: Casual · Pixel Graphics · Adventure

VVVVVV
Shared: Pixel Graphics · 2D Platformer · Platformer

The Messenger
Shared: Pixel Graphics · Platformer · Retro

Reventure
Shared: Adventure · Pixel Graphics · Indie

Downwell
Shared: Pixel Graphics · 2D Platformer · Platformer

Laughing to Die
Shared: Casual · Adventure · 2D Platformer

Braid
Shared: 2D Platformer · Puzzle Platformer · Platformer

LIMBO
Shared: Puzzle Platformer · Platformer · Adventure

Sonic Mania
Shared: Pixel Graphics · Platformer · 2D

Chained Together
Shared: Adventure · Casual · Platformer

Planet of Lana
Shared: 2D Platformer · Puzzle Platformer · Adventure

Rain World
Shared: Pixel Graphics · Platformer · Adventure