Games like The 9th Gate
Games like The 9th Gate include Outlast, Dead by Daylight, Outlast 2, The Outlast Trials, and Amnesia: The Dark Descent. We matched them by the tags players give The 9th Gate on Steam (Action, Gore, Indie, Simulation, and Horror): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: Horror · Gore · Survival Horror

Dead by Daylight
Shared: Gore · Horror · Survival Horror

Outlast 2
Shared: Horror · Gore · Psychological Horror

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

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

Resident Evil 7 Biohazard
Shared: Horror · Gore · Survival Horror

Resident Evil Village
Shared: Action · Horror · Survival Horror

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

Alien: Isolation
Shared: Horror · Survival Horror · Stealth

SOMA
Shared: Horror · Psychological Horror · Gore

Manhunt
Shared: Gore · Action · Horror

Dying Light
Shared: Horror · Survival Horror · Gore

The Evil Within
Shared: Gore · Horror · Action

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

The Evil Within 2
Shared: Horror · Action · Psychological Horror

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

Amnesia: The Bunker
Shared: Horror · Survival Horror · Stealth

DEVOUR
Shared: Horror · Survival Horror · Psychological Horror

CASE: Animatronics
Shared: Horror · Indie · Survival Horror

The Beast Inside
Shared: Horror · Action · Survival Horror

Granny Remake
Shared: Horror · Action · Survival Horror

Poppy Playtime
Shared: Horror · Survival Horror · Psychological Horror

Ultimate Custom Night
Shared: Horror · Survival Horror · Indie

Lobotomy Corporation | Monster Management Simulation
Shared: Simulation · Psychological Horror · Gore