Games like Mushroom 11
Games like Mushroom 11 include LIMBO, Hollow Knight, BEEP, Human Fall Flat, and Defy Gravity Extended. We matched them by the tags players give Mushroom 11 on Steam (Indie, Action, Adventure, Puzzle, and Platformer): closest matches first, and among equally close ones the better-known games.

LIMBO
Shared: Indie · Puzzle · Puzzle Platformer

Hollow Knight
Shared: Platformer · Indie · Adventure

BEEP
Shared: Indie · Adventure · Platformer

Human Fall Flat
Shared: Puzzle · Adventure · Physics

Defy Gravity Extended
Shared: Indie · Platformer · Puzzle Platformer

Planet of Lana
Shared: Action · Puzzle Platformer · Puzzle

Deadlight
Shared: Action · Indie · Platformer

Out There Somewhere
Shared: Indie · Platformer · Puzzle

BADLAND: Game of the Year Edition
Shared: Indie · Adventure · Action

Seen
Shared: Indie · Adventure · Puzzle

Hollow Knight: Silksong
Shared: Indie · Platformer · Adventure

Nihilumbra
Shared: Indie · Adventure · Puzzle

ANIMAL WELL
Shared: Puzzle · Platformer · Puzzle Platformer

FAR: Lone Sails
Shared: Adventure · Indie · Puzzle

Rain World
Shared: Indie · Platformer · Atmospheric

Neva
Shared: Adventure · Indie · Platformer

Portal 2
Shared: Puzzle · Platformer · Puzzle Platformer

Little Nightmares
Shared: Adventure · Indie · Puzzle Platformer

GRIS
Shared: Indie · Adventure · Atmospheric

MO:Astray
Shared: Indie · Action · Adventure

Teslagrad
Shared: Indie · Puzzle · Platformer

Ori and the Will of the Wisps
Shared: Platformer · Action · Adventure

Oddworld: New 'n' Tasty
Shared: Adventure · Platformer · Puzzle Platformer

Nine Sols
Shared: Action · Platformer · Indie