Games like ABYSS
Games like ABYSS include R.E.P.O., Escape the Backrooms, Lethal Company, Phasmophobia, and PEAK. We matched them by the tags players give ABYSS on Steam (Action, 3D, First-Person, Horror, and Submarine): closest matches first, and among equally close ones the better-known games.

R.E.P.O.
Shared: Horror · Online Co-Op · First-Person

Escape the Backrooms
Shared: Horror · Online Co-Op · First-Person

Lethal Company
Shared: First-Person · Horror · Online Co-Op

Phasmophobia
Shared: Horror · Online Co-Op · First-Person

PEAK
Shared: Online Co-Op · First-Person · 3D

KLETKA
Shared: Horror · First-Person · Action

Dying Light
Shared: Horror · Online Co-Op · First-Person

Five Nights at Freddy's: Security Breach
Shared: Horror · First-Person · 3D

Content Warning
Shared: Horror · Online Co-Op · First-Person

Buckshot Roulette
Shared: Horror · First-Person · 3D

Five Nights at Freddy's: Secret of the Mimic
Shared: First-Person · Horror · Action

Zort
Shared: Horror · Online Co-Op · First-Person

GONE Fishing
Shared: Action · Horror · First-Person

Left 4 Dead 2
Shared: Action · Online Co-Op · Horror

How to Fish
Shared: Online Co-Op · First-Person · Indie

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

Backrooms: Escape Together
Shared: Horror · Online Co-Op · First-Person

Dead by Daylight
Shared: Horror · Online Co-Op · First-Person

Pacify
Shared: Horror · Online Co-Op · First-Person

Starship Troopers: Extermination
Shared: Action · Online Co-Op · First-Person

The Headliners
Shared: Horror · Action · Online Co-Op

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

Metel - Horror Escape
Shared: Horror · First-Person · 3D

Chained in the Backrooms
Shared: Action · Horror · Online Co-Op