Games like Primal One
Games like Primal One include Five Nights at Freddy's: Security Breach, Outlast, Poppy Playtime, Escape the Backrooms, and The Forest. We matched them by the tags players give Primal One on Steam (Horror, Adventure, Survival Horror, Action, and First-Person): closest matches first, and among equally close ones the better-known games.

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

Outlast
Shared: Horror · Survival Horror · First-Person

Poppy Playtime
Shared: Horror · Survival Horror · Singleplayer

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

The Forest
Shared: Horror · Adventure · Survival Horror

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

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

Resident Evil Village
Shared: Horror · Survival Horror · First-Person

The Beast Inside
Shared: Horror · Adventure · Survival Horror

Resident Evil Requiem
Shared: Horror · Survival Horror · Action

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

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

Dark Deception
Shared: Horror · First-Person · Singleplayer

Alien: Isolation
Shared: Horror · Survival Horror · First-Person

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

Darkwood
Shared: Horror · Adventure · Survival Horror

Ultimate Custom Night
Shared: Horror · Survival Horror · Singleplayer

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

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

The Outlast Trials
Shared: Horror · Survival Horror · First-Person

Dying Light
Shared: Horror · Survival Horror · First-Person

Bendy and the Ink Machine
Shared: Horror · First-Person · Survival Horror

Penumbra Overture
Shared: Horror · Adventure · Survival Horror

Resident Evil 4
Shared: Horror · Survival Horror · Action