Games like Nightmare Manor
Games like Nightmare Manor include Outlast, Resident Evil Requiem, Poppy Playtime, Half-Life 2, and METRO 2033 Redux. We matched them by the tags players give Nightmare Manor on Steam (Action, Adventure, Horror, Shooter, and First-Person): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: Horror · First-Person · Atmospheric

Resident Evil Requiem
Shared: Horror · Action · First-Person

Poppy Playtime
Shared: Horror · First-Person · Dark

Half-Life 2
Shared: Action · Shooter · Adventure

METRO 2033 Redux
Shared: Action · Horror · Atmospheric

Choo-Choo Charles
Shared: Horror · First-Person · Shooter

BioShock Infinite
Shared: Action · Shooter · First-Person

METRO Last Light Redux
Shared: Action · Horror · Atmospheric

Ready or Not
Shared: Shooter · Horror · Action

Atomic Heart
Shared: Adventure · Action · Horror

Bendy and the Dark Revival
Shared: Horror · Action · First-Person

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

Black Mesa
Shared: Action · First-Person · Shooter

Metro Exodus
Shared: Action · Horror · First-Person

The Forest
Shared: Horror · Adventure · Action

BONEWORKS
Shared: Action · Physics · Shooter

Five Nights at Freddy's: Secret of the Mimic
Shared: Horror · Adventure · Action

Grand Theft Auto V Legacy
Shared: Action · Adventure · First-Person

VLADiK BRUTAL
Shared: Action · Shooter · First-Person

BioShock™ Remastered
Shared: Horror · Action · First-Person

Serious Sam: Siberian Mayhem
Shared: Action · Adventure · Shooter

PEAK
Shared: Adventure · Physics · First-Person

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

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