Games like Nine Floors
Games like Nine Floors include What Remains of Edith Finch, Firewatch, The Exit 8, Scanner Sombre, and Outer Wilds. We matched them by the tags players give Nine Floors on Steam (Exploration, Walking Simulator, Action-Adventure, Psychological Horror, and Adventure): closest matches first, and among equally close ones the better-known games.

What Remains of Edith Finch
Shared: Walking Simulator · Exploration · Adventure

Firewatch
Shared: Walking Simulator · Adventure · Exploration

The Exit 8
Shared: Exploration · Walking Simulator · Psychological Horror

Scanner Sombre
Shared: Exploration · Walking Simulator · Adventure

Outer Wilds
Shared: Exploration · Adventure · Mystery

POOLS
Shared: Walking Simulator · Psychological Horror · Exploration

Platform 8
Shared: Walking Simulator · Psychological Horror · Adventure

The Witness
Shared: Exploration · Walking Simulator · Indie

Layers of Fear (2016)
Shared: Walking Simulator · Psychological Horror · Adventure

INFRA
Shared: Exploration · Walking Simulator · Adventure

Amnesia: A Machine For Pigs
Shared: Walking Simulator · Exploration · Psychological Horror

Psalm 5:9-13
Shared: Exploration · Psychological Horror · Walking Simulator

Riven
Shared: Exploration · Adventure · Walking Simulator

Blue Prince
Shared: Exploration · Mystery · Singleplayer

Slime Rancher
Shared: Exploration · Adventure · Singleplayer

Escape the Backrooms
Shared: Psychological Horror · Exploration · Adventure

Cairn
Shared: Exploration · Adventure · Indie

The Unfinished Swan
Shared: Exploration · Adventure · Indie

DREDGE
Shared: Exploration · Adventure · Psychological Horror

Fears to Fathom - Woodbury Getaway
Shared: Psychological Horror · Adventure · Walking Simulator

Don't Play This
Shared: Exploration · Psychological Horror · Indie

Amnesia: Rebirth
Shared: Action-Adventure · Exploration · Adventure

Bright Lights of Svetlov
Shared: Walking Simulator · Exploration · Adventure

Obduction
Shared: Exploration · Adventure · Indie