Games like Liminal Protocol
Games like Liminal Protocol include Lethal Company, PILGRIM, KLETKA, Zort, and The Outlast Trials. We matched them by the tags players give Liminal Protocol on Steam (Dungeon Crawler, Roguelite, PvE, Action-Adventure, and 3D): closest matches first, and among equally close ones the better-known games.

Lethal Company
Shared: First-Person · Horror · PvE

PILGRIM
Shared: Dungeon Crawler · PvE · Horror

KLETKA
Shared: PvE · Horror · First-Person

Zort
Shared: Horror · PvE · First-Person

The Outlast Trials
Shared: Horror · PvE · First-Person

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

MIMESIS
Shared: PvE · Roguelite · Psychological Horror

Deadzone: Rogue
Shared: PvE · Roguelite · Dungeon Crawler

Five Nights at Freddy's: Secret of the Mimic
Shared: First-Person · Horror · 3D

CloverPit
Shared: Roguelite · First-Person · 3D

Psychopomp
Shared: Dungeon Crawler · Horror · First-Person

SILENT HILL: Townfall
Shared: Horror · First-Person · Action-Adventure

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

Poppy Playtime
Shared: Horror · First-Person · Psychological Horror

Pacify
Shared: Horror · First-Person · Psychological Horror

MiSide
Shared: Psychological Horror · First-Person · Horror

Shape of Dreams
Shared: PvE · Roguelite · Dungeon Crawler

Labyrinthine
Shared: Horror · Psychological Horror · First-Person

PANICORE
Shared: Horror · PvE · First-Person

Garten of Banban
Shared: Horror · First-Person · 3D

Warhammer 40,000: Space Marine 2
Shared: PvE · Action-Adventure · Action

Labyrinth Of The Demon King
Shared: Dungeon Crawler · First-Person · Horror

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

Phasmophobia
Shared: Horror · Psychological Horror · First-Person