Games like Outlast: Whistleblower DLC
Games like Outlast: Whistleblower DLC include Outlast, Outlast 2, Resident Evil Village, Resident Evil 7 Biohazard, and Amnesia: The Dark Descent. We matched them by the tags players give Outlast: Whistleblower DLC on Steam (Horror, Gore, Action, Atmospheric, and Adventure): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: Horror · Atmospheric · Gore

Outlast 2
Shared: Horror · Gore · Survival Horror

Resident Evil Village
Shared: Horror · Action · Survival Horror

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

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

Dead by Daylight
Shared: Horror · Gore · Survival Horror

The Beast Inside
Shared: Horror · Adventure · Action

Poppy Playtime
Shared: Horror · Singleplayer · Survival Horror

The Forest
Shared: Horror · Adventure · Action

SOMA
Shared: Horror · Atmospheric · Gore

The Outlast Trials
Shared: Horror · Survival Horror · Action

Dying Light
Shared: Horror · Survival Horror · Gore

METRO 2033 Redux
Shared: Horror · Atmospheric · Action

The Evil Within 2
Shared: Horror · Action · Gore

Clive Barker's Hellraiser: Revival
Shared: Gore · Horror · Action

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

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

The Evil Within
Shared: Horror · Gore · Atmospheric

DEVOUR
Shared: Horror · Survival Horror · Psychological Horror

Alien: Isolation
Shared: Horror · Atmospheric · Survival Horror

Resident Evil 2
Shared: Horror · Gore · Survival Horror

Scorn
Shared: Horror · Gore · Atmospheric

Little Nightmares
Shared: Horror · Atmospheric · Adventure

Resident Evil 4
Shared: Horror · Action · Survival Horror