Games like The Schism
Games like The Schism include Lethal Company, SOMA, The Outlast Trials, Outlast, and Alien: Isolation. We matched them by the tags players give The Schism on Steam (Horror, Demons, Sci-fi, Atmospheric, and Nonlinear): closest matches first, and among equally close ones the better-known games.

Lethal Company
Shared: Horror · Sci-fi · Psychological Horror

SOMA
Shared: Horror · Atmospheric · Sci-fi

The Outlast Trials
Shared: Horror · Psychological Horror · Stealth

Outlast
Shared: Horror · Atmospheric · Psychological Horror

Alien: Isolation
Shared: Horror · Sci-fi · Atmospheric

Pacify
Shared: Horror · Psychological Horror · Sci-fi

ROUTINE
Shared: Sci-fi · Atmospheric · Horror

Phasmophobia
Shared: Horror · Psychological Horror · Demons

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

Little Nightmares II
Shared: Horror · Atmospheric · Psychological Horror

Little Nightmares
Shared: Horror · Atmospheric · Stealth

Species: Unknown
Shared: Horror · Atmospheric · Stealth

Zort
Shared: Horror · Psychological Horror · Atmospheric

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

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

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

Inside the Backrooms
Shared: Horror · Psychological Horror · Atmospheric

Five Nights at Freddy's: Secret of the Mimic
Shared: Horror · Atmospheric · First-Person

Poppy Playtime
Shared: Horror · Psychological Horror · Dark

Iron Lung
Shared: Horror · Atmospheric · Psychological Horror

Nuclear Nightmare
Shared: Horror · Atmospheric · Psychological Horror

Subnautica 2
Shared: Horror · Atmospheric · Exploration

Prey
Shared: Sci-fi · Horror · Atmospheric

Visage
Shared: Horror · Psychological Horror · Atmospheric