Games like T.W.I.R.L.
Games like T.W.I.R.L. include Mouthwashing, The Beginner's Guide, Layers of Fear (2016), What Remains of Edith Finch, and Outlast. We matched them by the tags players give T.W.I.R.L. on Steam (Psychological Horror, Walking Simulator, Atmospheric, Emotional, and Multiple Endings): closest matches first, and among equally close ones the better-known games.

Mouthwashing
Shared: Psychological Horror · Atmospheric · Walking Simulator

The Beginner's Guide
Shared: Walking Simulator · Atmospheric · Indie

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

What Remains of Edith Finch
Shared: Walking Simulator · Atmospheric · Psychological Horror

Outlast
Shared: Psychological Horror · Atmospheric · Horror

No, I'm not a Human
Shared: Psychological Horror · Atmospheric · Multiple Endings

SOMA
Shared: Psychological Horror · Atmospheric · Horror

Still Wakes the Deep
Shared: Psychological Horror · Walking Simulator · Atmospheric

Blair Witch
Shared: Psychological Horror · Walking Simulator · Adventure

Visage
Shared: Psychological Horror · Atmospheric · Dark

ROUTINE
Shared: Psychological Horror · Atmospheric · Dark

Firewatch
Shared: Atmospheric · Walking Simulator · Adventure

Layers of Fear 2 (2019)
Shared: Psychological Horror · Atmospheric · Walking Simulator

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

Iron Lung
Shared: Psychological Horror · Atmospheric · Horror

Sally Face - Episode One
Shared: Psychological Horror · Atmospheric · Indie

OMORI
Shared: Psychological Horror · Multiple Endings · Indie

Welcome to Kowloon
Shared: Psychological Horror · Atmospheric · Walking Simulator

From The Darkness
Shared: Psychological Horror · Walking Simulator · Atmospheric

Summer of '58
Shared: Psychological Horror · Atmospheric · Walking Simulator

Slender: The Arrival
Shared: Psychological Horror · Atmospheric · Walking Simulator

Fears to Fathom - Ironbark Lookout
Shared: Psychological Horror · Atmospheric · Walking Simulator

INSIDE
Shared: Atmospheric · Dark · Indie

SILENT HILL 2
Shared: Psychological Horror · Atmospheric · Horror