Games like Slidungeon
Games like Slidungeon include Celeste, Hollow Knight, Rain World, Super Meat Boy, and LIMBO. We matched them by the tags players give Slidungeon on Steam (Difficult, Precision Platformer, Puzzle Platformer, Platformer, and Atmospheric): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Difficult · Precision Platformer · Platformer

Hollow Knight
Shared: Difficult · Platformer · Atmospheric

Rain World
Shared: Difficult · Atmospheric · Platformer

Super Meat Boy
Shared: Precision Platformer · Difficult · Platformer

LIMBO
Shared: Puzzle Platformer · Platformer · Atmospheric

Hollow Knight: Silksong
Shared: Difficult · Platformer · 2D

Geometry Dash
Shared: Difficult · Precision Platformer · Platformer

Braid
Shared: Puzzle Platformer · Platformer · 2D Platformer

VVVVVV
Shared: Precision Platformer · Platformer · Difficult

Jump King
Shared: Difficult · Precision Platformer · Platformer

ANIMAL WELL
Shared: Puzzle Platformer · Platformer · Exploration

Leap Year
Shared: Precision Platformer · Puzzle Platformer · 2D Platformer

MIO: Memories in Orbit
Shared: Platformer · Atmospheric · Difficult

Thomas Was Alone
Shared: Platformer · Precision Platformer · Puzzle Platformer

SANABI
Shared: 2D Platformer · Difficult · Platformer

FEZ
Shared: Platformer · Exploration · Puzzle Platformer

The End Is Nigh
Shared: Precision Platformer · Difficult · Platformer

Webbed
Shared: 2D Platformer · Puzzle Platformer · Platformer

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

Will You Snail?
Shared: Difficult · Precision Platformer · Platformer

GRIS
Shared: Atmospheric · Platformer · Indie

INSIDE
Shared: Puzzle Platformer · Atmospheric · Singleplayer

Aeterna Noctis
Shared: Difficult · Platformer · Precision Platformer

Little Nightmares
Shared: Atmospheric · Puzzle Platformer · Singleplayer