Games like Undead Hunter Part I
Games like Undead Hunter Part I include Ready or Not, DOOM, Left 4 Dead 2, Black Mesa, and Resident Evil Requiem. We matched them by the tags players give Undead Hunter Part I on Steam (Action, Shooter, Horror, Realistic, and FPS): closest matches first, and among equally close ones the better-known games.

Ready or Not
Shared: Shooter · Realistic · FPS

DOOM
Shared: Action · Shooter · FPS

Left 4 Dead 2
Shared: Shooter · FPS · Action

Black Mesa
Shared: Action · FPS · Shooter

Resident Evil Requiem
Shared: Horror · Action · FPS

Call of Duty®
Shared: Shooter · Action · FPS

Insurgency: Sandstorm
Shared: Shooter · Realistic · FPS

METRO 2033 Redux
Shared: FPS · Action · Horror

Bodycam
Shared: Realistic · FPS · Shooter

METRO Last Light Redux
Shared: Action · FPS · Horror

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

Half-Life 2
Shared: Action · FPS · Shooter

DOOM 3
Shared: Action · Horror · Shooter

BioShock™ Remastered
Shared: FPS · Horror · Action

BioShock Infinite
Shared: Action · Shooter · FPS

Insurgency
Shared: Realistic · FPS · Shooter

DOOM 3
Shared: Action · Horror · FPS

BioShock™
Shared: Action · FPS · Horror

Left 4 Dead
Shared: Action · FPS · Horror

DOOM Eternal
Shared: Action · FPS · Shooter

Arma 3
Shared: Action · Shooter · Realistic

Call of Duty®: Black Ops III
Shared: Shooter · Action · FPS

Squad
Shared: Realistic · FPS · Shooter

Metro Exodus
Shared: FPS · Action · Horror