Games like Slime Story
Games like Slime Story include Chained Together, Refunct, Portal 2, LIMBO, and Haste. We matched them by the tags players give Slime Story on Steam (Adventure, Platformer, 3D Platformer, Puzzle Platformer, and Runner): closest matches first, and among equally close ones the better-known games.

Chained Together
Shared: Adventure · Platformer · Puzzle Platformer

Refunct
Shared: 3D Platformer · Parkour · Puzzle Platformer

Portal 2
Shared: Platformer · Puzzle Platformer · 3D Platformer

LIMBO
Shared: Puzzle Platformer · Platformer · Adventure

Haste
Shared: 3D Platformer · Parkour · Runner

Neon White
Shared: 3D Platformer · Platformer · Parkour

Mirror's Edge™ Catalyst
Shared: Parkour · Runner · 3D Platformer

Pseudoregalia
Shared: 3D Platformer · Platformer · Parkour

Tomb Raider IV-VI Remastered
Shared: Adventure · Platformer · 3D Platformer

Celeste
Shared: Platformer · Precision Platformer · Adventure

White Knuckle
Shared: Parkour · 3D Platformer · Platformer

A Story About My Uncle
Shared: Adventure · Parkour · Platformer

VHOLUME
Shared: 3D Platformer · Parkour · Platformer

The Pedestrian
Shared: Puzzle Platformer · Platformer · Logic

Hot Lava
Shared: 3D Platformer · Parkour · Precision Platformer

Climber Animals: Together
Shared: Platformer · Puzzle Platformer · 3D Platformer

A Hat in Time
Shared: 3D Platformer · Adventure · Platformer

ALTF4
Shared: Runner · 3D Platformer · Platformer

Sonic Frontiers
Shared: Adventure · 3D Platformer · Platformer

Supraland
Shared: Adventure · Puzzle Platformer · 3D Platformer

FEZ
Shared: Platformer · Adventure · Puzzle Platformer

SEUM: Speedrunners from Hell
Shared: 3D Platformer · Platformer · Parkour

ANIMAL WELL
Shared: Platformer · Puzzle Platformer · Adventure

Phantom Abyss
Shared: Adventure · 3D Platformer · Platformer