Games like INTUS
Games like INTUS include Firewatch, What Remains of Edith Finch, Mouthwashing, Amnesia: A Machine For Pigs, and Layers of Fear (2016). We matched them by the tags players give INTUS on Steam (Psychological Horror, Horror, Walking Simulator, First-Person, and Atmospheric): closest matches first, and among equally close ones the better-known games.

Firewatch
Shared: Walking Simulator · Atmospheric · First-Person

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

Mouthwashing
Shared: Psychological Horror · Horror · Atmospheric

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

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

SOMA
Shared: Psychological Horror · Horror · Atmospheric

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

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

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

Still Wakes the Deep
Shared: Psychological Horror · Horror · First-Person

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

MiSide
Shared: Psychological Horror · Horror · First-Person

Outlast
Shared: Horror · First-Person · Psychological Horror

DON'T SCREAM
Shared: Psychological Horror · Horror · First-Person

Poppy Playtime
Shared: Horror · First-Person · Psychological Horror

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

Visage
Shared: Psychological Horror · Horror · First-Person

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

The Beginner's Guide
Shared: Walking Simulator · First-Person · Atmospheric

Gone Home
Shared: Walking Simulator · Atmospheric · First-Person

Scanner Sombre
Shared: Horror · Walking Simulator · Exploration

Fears to Fathom - Norwood Hitchhike
Shared: Psychological Horror · Horror · Atmospheric

Outer Wilds
Shared: Exploration · Atmospheric · Story Rich

The Suicide of Rachel Foster
Shared: Walking Simulator · Atmospheric · Thriller