Games like Maple Ridge
Games like Maple Ridge include Firewatch, Fears to Fathom - Ironbark Lookout, Layers of Fear (2016), Mouthwashing, and SOMA. We matched them by the tags players give Maple Ridge on Steam (Horror, Adventure, Psychological Horror, Atmospheric, and Walking Simulator): closest matches first, and among equally close ones the better-known games.

Firewatch
Shared: Adventure · Atmospheric · Walking Simulator

Fears to Fathom - Ironbark Lookout
Shared: Horror · Psychological Horror · Atmospheric

Layers of Fear (2016)
Shared: Horror · Psychological Horror · Atmospheric

Mouthwashing
Shared: Horror · Psychological Horror · Atmospheric

SOMA
Shared: Horror · Psychological Horror · Atmospheric

Outlast
Shared: Horror · Atmospheric · Psychological Horror

What Remains of Edith Finch
Shared: Atmospheric · Walking Simulator · Adventure

Still Wakes the Deep
Shared: Horror · Psychological Horror · Walking Simulator

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

MiSide
Shared: Psychological Horror · Horror · First-Person

Amnesia: A Machine For Pigs
Shared: Horror · Walking Simulator · Atmospheric

Lethal Company
Shared: Horror · First-Person · Psychological Horror

Blair Witch
Shared: Horror · Adventure · Psychological Horror

Fears to Fathom - Woodbury Getaway
Shared: Adventure · Horror · Psychological Horror

Visage
Shared: Horror · Psychological Horror · Adventure

The Park®
Shared: Horror · Psychological Horror · Walking Simulator

Welcome to Kowloon
Shared: Horror · Psychological Horror · Adventure

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

The Beast Inside
Shared: Horror · Adventure · First-Person

The Exit 8
Shared: Horror · Walking Simulator · Psychological Horror

Scanner Sombre
Shared: Horror · Adventure · Walking Simulator

Amnesia: The Dark Descent
Shared: Horror · Psychological Horror · Atmospheric

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

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