Games like No Nap November
Games like No Nap November include Mouthwashing, No, I'm not a Human, SOMA, Outlast, and Poppy Playtime. We matched them by the tags players give No Nap November on Steam (Psychological Horror, Walking Simulator, Horror, Hidden Object, and Atmospheric): closest matches first, and among equally close ones the better-known games.

Mouthwashing
Shared: Psychological Horror · Horror · Atmospheric

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

SOMA
Shared: Psychological Horror · Horror · Atmospheric

Outlast
Shared: Horror · Psychological Horror · Atmospheric

Poppy Playtime
Shared: Horror · Psychological Horror · Survival Horror

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

Firewatch
Shared: Walking Simulator · Atmospheric · Adventure

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

Visage
Shared: Psychological Horror · Horror · Survival Horror

SILENT HILL 2
Shared: Psychological Horror · Horror · Atmospheric

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

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

MiSide
Shared: Psychological Horror · Horror · Atmospheric

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

Five Nights at Freddy's
Shared: Horror · Psychological Horror · Survival Horror

The Cabin Factory
Shared: Psychological Horror · Horror · Walking Simulator

Scanner Sombre
Shared: Walking Simulator · Horror · Psychological Horror

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

Kholat
Shared: Horror · Walking Simulator · Psychological Horror

Garten of Banban
Shared: Horror · Psychological Horror · Singleplayer

Lethal Company
Shared: Horror · Psychological Horror · Survival Horror

The Park®
Shared: Psychological Horror · Horror · Walking Simulator

Escape the Backrooms
Shared: Horror · Psychological Horror · Survival Horror

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