Games like TARTARUS
Games like TARTARUS include Outer Wilds, Deliver Us The Moon, The Talos Principle, No Man's Sky, and Half-Life 2. We matched them by the tags players give TARTARUS on Steam (Indie, Adventure, Action, Puzzle, and Sci-fi): closest matches first, and among equally close ones the better-known games.

Outer Wilds
Shared: Adventure · Space · Puzzle

Deliver Us The Moon
Shared: Indie · Adventure · Action

The Talos Principle
Shared: Puzzle · Sci-fi · First-Person

No Man's Sky
Shared: Sci-fi · Space · Adventure

Half-Life 2
Shared: Action · Sci-fi · Adventure

Black Mesa
Shared: Action · Sci-fi · First-Person

Poppy Playtime
Shared: Puzzle · Singleplayer · First-Person

A Story About My Uncle
Shared: Adventure · Indie · First-Person

Observation
Shared: Indie · Adventure · Sci-fi

Fallout 4
Shared: Adventure · Singleplayer · Atmospheric

Breathedge
Shared: Indie · Space · Singleplayer

Stray
Shared: Adventure · Atmospheric · Puzzle

Rise of the Tomb Raider™
Shared: Adventure · Action · Singleplayer

Firewatch
Shared: Adventure · Atmospheric · Indie

Bendy and the Dark Revival
Shared: Action · Adventure · Indie

The Turing Test
Shared: Puzzle · Sci-fi · Adventure

BioShock Infinite
Shared: Action · First-Person · Adventure

Return of the Obra Dinn
Shared: Puzzle · Indie · Atmospheric

Valley
Shared: Adventure · Indie · First-Person

Alien: Isolation
Shared: Sci-fi · Atmospheric · First-Person

Brothers - A Tale of Two Sons
Shared: Adventure · Indie · Atmospheric

FAR: Lone Sails
Shared: Adventure · Atmospheric · Indie

STAR WARS Jedi: Survivor™
Shared: Action · Adventure · Singleplayer

Antichamber
Shared: Indie · Puzzle · First-Person

