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

Phasmophobia
Shared: Online Co-Op · Multiplayer · Horror

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

Pacify
Shared: Online Co-Op · Multiplayer · Horror

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

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

Inside the Backrooms
Shared: Multiplayer · Horror · Psychological Horror

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

The Outlast Trials
Shared: Multiplayer · Horror · Psychological Horror

Demonologist
Shared: Multiplayer · Horror · Online Co-Op

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

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

DEVOUR
Shared: Online Co-Op · Multiplayer · Horror

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

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

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

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

PEAK
Shared: Multiplayer · Online Co-Op · Exploration

Ready or Not
Shared: Multiplayer · Horror · FPS

Outlast
Shared: Horror · Psychological Horror · Multiplayer

Species: Unknown
Shared: Online Co-Op · Horror · Multiplayer

GTFO
Shared: Online Co-Op · Horror · Multiplayer

BIGFOOT
Shared: Multiplayer · Horror · Online Co-Op

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

PANICORE
Shared: Online Co-Op · Horror · Multiplayer