Games like Deep Under the Sky
Games like Deep Under the Sky include Portal 2, Defy Gravity Extended, LIMBO, Portal, and Zup!. We matched them by the tags players give Deep Under the Sky on Steam (Arcade, Physics, Puzzle, Platformer, and Relaxing): closest matches first, and among equally close ones the better-known games.

Portal 2
Shared: Puzzle · Platformer · Puzzle Platformer

Defy Gravity Extended
Shared: Platformer · Puzzle · Puzzle Platformer

LIMBO
Shared: Puzzle · Platformer · Puzzle Platformer

Portal
Shared: Puzzle · Puzzle Platformer · Physics

Zup!
Shared: Puzzle · Physics · Relaxing

Superliminal
Shared: Puzzle · Physics · Surreal

Zup! S
Shared: Puzzle · Physics · Relaxing

Peggle Deluxe
Shared: Arcade · Puzzle · Physics

Viewfinder
Shared: Puzzle · Puzzle Platformer · Physics

Human Fall Flat
Shared: Puzzle · Physics · Puzzle Platformer

Webbed
Shared: Physics · Platformer · Puzzle Platformer

BEEP
Shared: Platformer · Physics · Puzzle

Zup! 3
Shared: Puzzle · Physics · Relaxing

GRIS
Shared: Platformer · Relaxing · Beautiful

Zup! 2
Shared: Puzzle · Physics · Relaxing

The Bridge
Shared: Physics · Puzzle · Puzzle Platformer

FEZ
Shared: Puzzle · Platformer · Indie

Manifold Garden
Shared: Puzzle · Psychedelic · Surreal

Trine 2: Complete Story
Shared: Platformer · Puzzle · Puzzle Platformer

Zup! 8
Shared: Puzzle · Physics · Relaxing

Zup! F
Shared: Puzzle · Physics · Relaxing

Monument Valley 3
Shared: Relaxing · Puzzle · Casual

Zup! X
Shared: Puzzle · Physics · Relaxing

Planet of Lana
Shared: Action · Puzzle · Puzzle Platformer