Games like Nix Umbra
Games like Nix Umbra include Devil Daggers, Ready or Not, Buckshot Roulette, METRO 2033 Redux, and METRO Last Light Redux. We matched them by the tags players give Nix Umbra on Steam (Horror, Indie, Gothic, Arena Shooter, and FPS): closest matches first, and among equally close ones the better-known games.

Devil Daggers
Shared: Indie · FPS · Horror

Ready or Not
Shared: FPS · Horror · Shooter

Buckshot Roulette
Shared: Horror · Indie · Dark

METRO 2033 Redux
Shared: Horror · FPS · Shooter

METRO Last Light Redux
Shared: FPS · Horror · Shooter

Left 4 Dead 2
Shared: FPS · Horror · Shooter

Outlast
Shared: Horror · First-Person · Indie

BioShock™ Remastered
Shared: Horror · FPS · Shooter

Choo-Choo Charles
Shared: Horror · Shooter · FPS

Trepang2
Shared: Horror · FPS · Shooter

HOLE
Shared: Horror · Indie · FPS

Aimlabs
Shared: FPS · Shooter · Indie

F.E.A.R.
Shared: Horror · FPS · Shooter

Half-Life: Alyx
Shared: Horror · FPS · Shooter

Poppy Playtime
Shared: Horror · Indie · Dark

Black Mesa
Shared: FPS · Shooter · First-Person

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

DOOM 3
Shared: Horror · FPS · Dark

AMID EVIL
Shared: FPS · Arena Shooter · Shooter

Receiver 2
Shared: FPS · Indie · Shooter

DOOM
Shared: FPS · Shooter · Horror

Gunfire Reborn
Shared: FPS · Roguelike · Indie

Metro Exodus
Shared: FPS · Horror · Shooter

DOOM 3
Shared: Horror · FPS · Shooter