Games like Deep Dark Space
Games like Deep Dark Space include Phasmophobia, Escape the Backrooms, Pacify, Dead by Daylight, and Lethal Company. We matched them by the tags players give Deep Dark Space on Steam (Horror, Multiplayer, Online Co-Op, Investigation, and Social Deduction): closest matches first, and among equally close ones the better-known games.

Phasmophobia
Shared: Horror · Multiplayer · Online Co-Op

Escape the Backrooms
Shared: Horror · Multiplayer · Online Co-Op

Pacify
Shared: Horror · Multiplayer · Online Co-Op

Dead by Daylight
Shared: Horror · Multiplayer · Online Co-Op

Lethal Company
Shared: Horror · Online Co-Op · Co-op

Demonologist
Shared: Horror · Multiplayer · Online Co-Op

Inside the Backrooms
Shared: Horror · Multiplayer · Online Co-Op

Among Us
Shared: Multiplayer · Online Co-Op · Social Deduction

DEVOUR
Shared: Horror · Multiplayer · Online Co-Op

Content Warning
Shared: Horror · Online Co-Op · Multiplayer

Backrooms: Escape Together
Shared: Horror · Multiplayer · Online Co-Op

Lunch Lady
Shared: Horror · Multiplayer · Online Co-Op

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

Left 4 Dead 2
Shared: Multiplayer · Online Co-Op · Co-op

PEAK
Shared: Multiplayer · Online Co-Op · Co-op

Nuclear Nightmare
Shared: Horror · Online Co-Op · Multiplayer

In Silence
Shared: Horror · Multiplayer · Online Co-Op

HELLDIVERS™ 2
Shared: Online Co-Op · Multiplayer · Co-op

The Outlast Trials
Shared: Horror · Multiplayer · Co-op

Subnautica 2
Shared: Multiplayer · Horror · Exploration

Dead Space™ 3
Shared: Horror · Online Co-Op · Co-op

Shift At Midnight
Shared: Horror · Multiplayer · Online Co-Op

BIGFOOT
Shared: Horror · Multiplayer · Online Co-Op

LOCKDOWN Protocol
Shared: Multiplayer · Social Deduction · Investigation