Games like Greyhill Incident
Games like Greyhill Incident include Outlast, Alien: Isolation, Poppy Playtime, SOMA, and Lethal Company. We matched them by the tags players give Greyhill Incident on Steam (Survival Horror, Horror, Aliens, First-Person, and Singleplayer): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: Horror · Survival Horror · First-Person

Alien: Isolation
Shared: Survival Horror · Horror · Aliens

Poppy Playtime
Shared: Horror · Singleplayer · Survival Horror

SOMA
Shared: Horror · Survival Horror · Atmospheric

Lethal Company
Shared: Horror · Survival Horror · First-Person

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

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

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

METRO 2033 Redux
Shared: Horror · Atmospheric · Singleplayer

Metro Exodus
Shared: Singleplayer · Horror · Atmospheric

Five Nights at Freddy's: Security Breach
Shared: Horror · Survival Horror · Singleplayer

METRO Last Light Redux
Shared: Horror · Atmospheric · Singleplayer

The Forest
Shared: Horror · Survival Horror · Adventure

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

Little Nightmares
Shared: Horror · Singleplayer · Adventure

Prey
Shared: Horror · Singleplayer · First-Person

Resident Evil Requiem
Shared: Survival Horror · Horror · First-Person

Firewatch
Shared: Adventure · Atmospheric · First-Person

Five Nights at Freddy's
Shared: Horror · Survival Horror · Singleplayer

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

Five Nights at Freddy's 2
Shared: Horror · Survival Horror · Singleplayer

Darkwood
Shared: Survival Horror · Horror · Adventure

Subnautica
Shared: Horror · Singleplayer · First-Person

Amnesia: The Dark Descent
Shared: Horror · Survival Horror · First-Person