Games like Gulman 4: Still alive
Games like Gulman 4: Still alive include Ready or Not, Outlast, DOOM, METRO 2033 Redux, and Trepang2. We matched them by the tags players give Gulman 4: Still alive on Steam (Psychological Horror, Action, Horror, Atmospheric, and FPS): closest matches first, and among equally close ones the better-known games.

Ready or Not
Shared: FPS · Shooter · Horror

Outlast
Shared: Horror · Psychological Horror · Atmospheric

DOOM
Shared: Action · FPS · Shooter

METRO 2033 Redux
Shared: Atmospheric · FPS · Horror

Trepang2
Shared: Horror · Shooter · FPS

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

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

Black Mesa
Shared: Action · FPS · First-Person

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

Metro Exodus
Shared: FPS · Action · Atmospheric

METRO Last Light Redux
Shared: Action · Atmospheric · FPS

BioShock Infinite
Shared: Action · Shooter · FPS

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

Outlast 2
Shared: Psychological Horror · Horror · First-Person

Call of Duty®
Shared: FPS · Action · Shooter

F.E.A.R. 2: Project Origin
Shared: Horror · Action · FPS

DOOM Eternal
Shared: Action · FPS · Gore

Half-Life 2
Shared: Action · FPS · Shooter

BioShock™ Remastered
Shared: FPS · Horror · Atmospheric

BioShock™
Shared: Action · Atmospheric · FPS

Left 4 Dead 2
Shared: FPS · Action · Shooter

In Sound Mind
Shared: Psychological Horror · Horror · Action

Battlefield™ 1
Shared: FPS · Action · Shooter

Blood and Bacon
Shared: Action · Shooter · Horror