Games like Spiritus Sancti
Games like Spiritus Sancti include Outlast, Poppy Playtime, SOMA, Outlast 2, and Escape the Backrooms. We matched them by the tags players give Spiritus Sancti on Steam (Horror, Adventure, Psychological Horror, Survival Horror, and Action): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: Horror · Survival Horror · Psychological Horror

Poppy Playtime
Shared: Horror · Survival Horror · Singleplayer

SOMA
Shared: Horror · Psychological Horror · Survival Horror

Outlast 2
Shared: Horror · Psychological Horror · Survival Horror

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

Darkwood
Shared: Horror · Adventure · Survival Horror

Resident Evil Requiem
Shared: Horror · Survival Horror · Action

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

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

Visage
Shared: Horror · Psychological Horror · Survival Horror

Resident Evil Village
Shared: Horror · Survival Horror · Action

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

Five Nights at Freddy's: Security Breach
Shared: Horror · Survival Horror · Singleplayer

Little Nightmares II
Shared: Horror · Adventure · Psychological Horror

The Forest
Shared: Horror · Adventure · Survival Horror

Bendy and the Dark Revival
Shared: Horror · Adventure · Survival Horror

The Beast Inside
Shared: Horror · Adventure · Survival Horror

SILENT HILL: Townfall
Shared: Horror · Adventure · Psychological Horror

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

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

Little Nightmares
Shared: Horror · Adventure · Atmospheric

Slender: The Arrival
Shared: Horror · Survival Horror · Psychological Horror

The Outlast Trials
Shared: Horror · Survival Horror · Psychological Horror

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