Games like The Guardian
Games like The Guardian include Celeste, Thomas Was Alone, Thank Goodness You're Here!, Geometry Dash, and Super Meat Boy. We matched them by the tags players give The Guardian on Steam (Casual, Adventure, Platformer, 2D Platformer, and Side Scroller): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Precision Platformer · Platformer · 2D Platformer

Thomas Was Alone
Shared: Platformer · Side Scroller · 2D Platformer

Thank Goodness You're Here!
Shared: Adventure · Casual · 2D Platformer

Geometry Dash
Shared: 2D · Platformer · Precision Platformer

Super Meat Boy
Shared: Platformer · Precision Platformer · 2D Platformer

Melvor Idle
Shared: Casual · Adventure · 2D

SANABI
Shared: Adventure · 2D Platformer · 2D

Trine Enchanted Edition
Shared: 2D Platformer · Colorful · Fantasy

Laughing to Die
Shared: Casual · Adventure · Platformer

Sonic Superstars
Shared: Platformer · Adventure · Casual

Dust: An Elysian Tail
Shared: Platformer · Adventure · 2D

Hue
Shared: Adventure · Platformer · Indie

Sonic Mania
Shared: Platformer · 2D · Adventure

Hollow Knight
Shared: Platformer · 2D · Adventure

Downwell
Shared: Precision Platformer · Platformer · 2D Platformer

Shovel Knight: Treasure Trove
Shared: Platformer · Adventure · 2D

Eastern Exorcist
Shared: Adventure · Side Scroller · 2D

LIMBO
Shared: Platformer · Adventure · Indie

Neva
Shared: Adventure · Platformer · 2D Platformer

Trine 2: Complete Story
Shared: Platformer · 2D Platformer · Casual

VVVVVV
Shared: Platformer · Precision Platformer · 2D Platformer

Super Fancy Pants Adventure
Shared: Adventure · Casual · Platformer

Songs for a Hero - Definitive Edition
Shared: Adventure · 2D Platformer · Platformer

Pikuniku
Shared: Adventure · Casual · Indie