Games like Door2:Key - Golden City DLC
Games like Door2:Key - Golden City DLC include The Witness, Outer Wilds, Firewatch, Antichamber, and The Long Dark. We matched them by the tags players give Door2:Key - Golden City DLC on Steam (Adventure, Indie, Puzzle, Open World, and Exploration): closest matches first, and among equally close ones the better-known games.

The Witness
Shared: Puzzle · Exploration · Open World

Outer Wilds
Shared: Adventure · Exploration · Puzzle

Firewatch
Shared: Adventure · Atmospheric · First-Person

Antichamber
Shared: Puzzle · Indie · First-Person

The Long Dark
Shared: Open World · Exploration · Adventure

Big Walk
Shared: Puzzle · Adventure · Open World

Fallout 4
Shared: Open World · Adventure · Exploration

Stray
Shared: Adventure · Exploration · Atmospheric

No Man's Sky
Shared: Open World · Exploration · Adventure

Obduction
Shared: Adventure · Puzzle · Indie

Slime Rancher
Shared: Adventure · Exploration · Open World

INFRA
Shared: Puzzle · Exploration · Adventure

Cradle
Shared: Adventure · Indie · Puzzle

Valley
Shared: Adventure · Exploration · Indie

The Forest
Shared: Adventure · Open World · First-Person

AER Memories of Old
Shared: Adventure · Indie · Exploration

What Remains of Edith Finch
Shared: Adventure · Atmospheric · Exploration

Chants of Sennaar
Shared: Adventure · Puzzle · Indie

The Talos Principle
Shared: Puzzle · First-Person · Adventure

FAR: Lone Sails
Shared: Adventure · Indie · Atmospheric

NaissanceE
Shared: Indie · Exploration · Adventure

COCOON
Shared: Adventure · Puzzle · Indie

Blue Prince
Shared: Puzzle · Exploration · Indie

The Unfinished Swan
Shared: Adventure · Puzzle · Indie