Games like The Attic
Games like The Attic include Outlast, Lethal Company, Layers of Fear (2016), SOMA, and What Remains of Edith Finch. We matched them by the tags players give The Attic on Steam (Horror, Psychological Horror, Walking Simulator, Surreal, and Atmospheric): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: Horror · Psychological Horror · Atmospheric

Lethal Company
Shared: Horror · First-Person · Psychological Horror

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

SOMA
Shared: Horror · Psychological Horror · Atmospheric

What Remains of Edith Finch
Shared: Walking Simulator · Atmospheric · First-Person

Mouthwashing
Shared: Horror · Psychological Horror · Atmospheric

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

Visage
Shared: Horror · Psychological Horror · First-Person

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

Escape the Backrooms
Shared: Horror · Psychological Horror · First-Person

SILENT HILL f
Shared: Horror · Psychological Horror · Female Protagonist

Slender: The Arrival
Shared: Horror · Psychological Horror · First-Person

Firewatch
Shared: Walking Simulator · Atmospheric · First-Person

NaissanceE
Shared: Walking Simulator · Atmospheric · Exploration

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

Resident Evil 7 Biohazard
Shared: Horror · First-Person · Psychological Horror

Fears to Fathom - Woodbury Getaway
Shared: Psychological Horror · Horror · Atmospheric

Backrooms: Escape Together
Shared: Horror · Psychological Horror · Atmospheric

Outlast 2
Shared: Horror · Psychological Horror · First-Person

Garten of Banban
Shared: Horror · Psychological Horror · First-Person

Amnesia: The Dark Descent
Shared: Horror · Psychological Horror · Atmospheric

[Chillas Art] The Convenience Store
Shared: Horror · Psychological Horror · Atmospheric

The Hat Man: Shadow Ward
Shared: Horror · Atmospheric · First-Person

The Beast Inside
Shared: Horror · First-Person · Psychological Horror