Games like Nightmare House: The Original Mod
Games like Nightmare House: The Original Mod include Poppy Playtime, Dark Deception, Little Nightmares II, Resident Evil 7 Biohazard, and Ultimate Custom Night. We matched them by the tags players give Nightmare House: The Original Mod on Steam (Free to Play, Horror, Action-Adventure, Indie, and Multiplayer): closest matches first, and among equally close ones the better-known games.

Poppy Playtime
Shared: Horror · Free to Play · First-Person

Dark Deception
Shared: Free to Play · Horror · Multiplayer

Little Nightmares II
Shared: Horror · Multiplayer · Action-Adventure

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

Ultimate Custom Night
Shared: Free to Play · Horror · Indie

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

Resident Evil Requiem
Shared: Horror · Zombies · Action-Adventure

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

Where Winds Meet
Shared: Free to Play · Multiplayer · Action-Adventure

We Were Here
Shared: Free to Play · Horror · Multiplayer

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

Outlast
Shared: Horror · First-Person · Multiplayer

The Beast Inside
Shared: Horror · Multiplayer · First-Person

Dying Light: The Beast
Shared: Horror · Multiplayer · Zombies

Amnesia: Rebirth
Shared: Action-Adventure · Horror · First-Person

Buckshot Roulette
Shared: Horror · Multiplayer · Indie

Apex Legends™
Shared: Free to Play · Multiplayer · First-Person

Outlast 2
Shared: Horror · First-Person · Multiplayer

Resident Evil 2
Shared: Horror · Zombies · Multiplayer

Halo Infinite
Shared: Free to Play · Multiplayer · First-Person

Layers of Fear (2016)
Shared: Horror · Indie · First-Person

Content Warning
Shared: Horror · Multiplayer · Physics

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

R.E.P.O.
Shared: Horror · Multiplayer · Physics