Games like The Backrooms : Last Expedition
Games like The Backrooms : Last Expedition include Escape the Backrooms, Backrooms: Escape Together, Lethal Company, Pacify, and Phasmophobia. We matched them by the tags players give The Backrooms : Last Expedition on Steam (Horror, Multiplayer, Psychological Horror, Online Co-Op, and Adventure): closest matches first, and among equally close ones the better-known games.

Escape the Backrooms
Shared: Horror · Multiplayer · Psychological Horror

Backrooms: Escape Together
Shared: Horror · Multiplayer · Psychological Horror

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

Pacify
Shared: Horror · Multiplayer · Online Co-Op

Phasmophobia
Shared: Horror · Multiplayer · Online Co-Op

Inside the Backrooms
Shared: Horror · Multiplayer · Psychological Horror

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

The Outlast Trials
Shared: Horror · Multiplayer · Psychological Horror

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

PEAK
Shared: Multiplayer · Online Co-Op · Adventure

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

Outlast
Shared: Horror · Psychological Horror · First-Person

DEVOUR
Shared: Horror · Multiplayer · Online Co-Op

Subnautica 2
Shared: Multiplayer · Horror · Survival Horror

Dying Light
Shared: Horror · Online Co-Op · Survival Horror

PANICORE
Shared: Horror · Online Co-Op · Psychological Horror

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

The Beast Inside
Shared: Horror · Multiplayer · Adventure

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

Emissary Zero
Shared: Horror · Multiplayer · Psychological Horror

BIGFOOT
Shared: Horror · Multiplayer · Online Co-Op

Sons Of The Forest
Shared: Multiplayer · Horror · Survival Horror

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

Fears to Fathom® - Scratch Creek
Shared: Horror · Multiplayer · Psychological Horror