Games like Project0
Games like Project0 include Lethal Company, Escape the Backrooms, Pacify, PEAK, and The Outlast Trials. We matched them by the tags players give Project0 on Steam (Action, Action-Adventure, Exploration, 3D, and First-Person): closest matches first, and among equally close ones the better-known games.

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

Escape the Backrooms
Shared: First-Person · Psychological Horror · Exploration

Pacify
Shared: Exploration · First-Person · Psychological Horror

PEAK
Shared: Exploration · First-Person · 3D

The Outlast Trials
Shared: First-Person · Action · Psychological Horror

Backrooms: Escape Together
Shared: Psychological Horror · First-Person · Survival Horror

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

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

Content Warning
Shared: Exploration · Procedural Generation · Action

Dead by Daylight
Shared: Survival Horror · Gore · First-Person

Far Cry® 5
Shared: Action-Adventure · Exploration · First-Person

Resident Evil Requiem
Shared: Action · Survival Horror · Action-Adventure

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

SILENT HILL: Townfall
Shared: Action · First-Person · Exploration

Nuclear Nightmare
Shared: First-Person · Survival Horror · Exploration

Phasmophobia
Shared: Psychological Horror · First-Person · Dark

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

Lunch Lady
Shared: Action · Dark · Survival Horror

Inside the Backrooms
Shared: Exploration · Survival Horror · Psychological Horror

Five Nights at Freddy's: Security Breach
Shared: First-Person · Exploration · Survival Horror

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

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

Hamster Hunter
Shared: Exploration · Action-Adventure · 3D

Funnel Runners
Shared: Exploration · Action-Adventure · Survival Horror