Games like 6 Keys: The Gym
Games like 6 Keys: The Gym include Garten of Banban, Outlast, Resident Evil 7 Biohazard, Resident Evil Village, and Phasmophobia. We matched them by the tags players give 6 Keys: The Gym on Steam (Hidden Object, Adventure, 3D, First-Person, and Horror): closest matches first, and among equally close ones the better-known games.

Garten of Banban
Shared: Horror · First-Person · VR

Outlast
Shared: First-Person · Horror · Adventure

Resident Evil 7 Biohazard
Shared: Horror · First-Person · VR

Resident Evil Village
Shared: First-Person · Horror · Singleplayer

Phasmophobia
Shared: Horror · VR · First-Person

Buckshot Roulette
Shared: Dark · First-Person · Horror

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

Poppy Playtime
Shared: Horror · First-Person · Singleplayer

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

Outlast 2
Shared: Horror · First-Person · Dark

Still Wakes the Deep
Shared: Horror · First-Person · Adventure

Granny
Shared: Horror · First-Person · VR

Choo-Choo Charles
Shared: Horror · First-Person · Singleplayer

Half-Life: Alyx
Shared: VR · Horror · First-Person

Home Sweet Home
Shared: Adventure · Horror · Gore

Scorn
Shared: Horror · First-Person · Gore

Firewatch
Shared: Adventure · First-Person · Singleplayer

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

Resident Evil Requiem
Shared: Horror · First-Person · Singleplayer

Visage
Shared: Horror · First-Person · Dark

MiSide
Shared: First-Person · Horror · 3D

Welcome to Kowloon
Shared: Adventure · Horror · First-Person

Garten of Banban 2
Shared: Horror · First-Person · Singleplayer

SOMA
Shared: Horror · Dark · First-Person