Games like The Collector
Games like The Collector include Ready or Not, Poppy Playtime, Escape the Backrooms, Outlast, and Lethal Company. We matched them by the tags players give The Collector on Steam (Horror, First-Person, Physics, FPS, and Mystery): closest matches first, and among equally close ones the better-known games.

Ready or Not
Shared: FPS · Horror · First-Person

Poppy Playtime
Shared: Horror · First-Person · Singleplayer

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

Outlast
Shared: Horror · First-Person · Psychological Horror

Lethal Company
Shared: Horror · First-Person · Exploration

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

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

Trepang2
Shared: Horror · FPS · First-Person

Metro Exodus
Shared: FPS · Horror · First-Person

Left 4 Dead 2
Shared: FPS · Horror · First-Person

Content Warning
Shared: Horror · Exploration · Physics

Half-Life 2
Shared: FPS · First-Person · Singleplayer

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

Amnesia: A Machine For Pigs
Shared: Horror · First-Person · Psychological Horror

METRO 2033 Redux
Shared: FPS · Horror · First-Person

Half-Life: Alyx
Shared: Horror · FPS · First-Person

Counter-Strike 2
Shared: FPS · First-Person · Shooter

Inside the Backrooms
Shared: Horror · Psychological Horror · First-Person

Call of Duty®
Shared: FPS · First-Person · Singleplayer

Phasmophobia
Shared: Horror · Psychological Horror · First-Person

Battlefield™ 2042
Shared: FPS · First-Person · Shooter

DOOM
Shared: FPS · First-Person · Shooter

Garry's Mod
Shared: Physics · First-Person · FPS

What Remains of Edith Finch
Shared: First-Person · Mystery · Exploration