Games like Inside The Forest
Games like Inside The Forest include SOMA, MiSide, Firewatch, What Remains of Edith Finch, and Layers of Fear (2016). We matched them by the tags players give Inside The Forest on Steam (Adventure, Horror, Psychological Horror, Story Rich, and First-Person): closest matches first, and among equally close ones the better-known games.

SOMA
Shared: Horror · Psychological Horror · Story Rich

MiSide
Shared: Psychological Horror · Story Rich · Horror

Firewatch
Shared: Adventure · Story Rich · Atmospheric

What Remains of Edith Finch
Shared: Story Rich · Adventure · Atmospheric

Layers of Fear (2016)
Shared: Horror · Psychological Horror · First-Person

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

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

No, I'm not a Human
Shared: Horror · Psychological Horror · Story Rich

Mouthwashing
Shared: Horror · Psychological Horror · Story Rich

Amnesia: A Machine For Pigs
Shared: Horror · Story Rich · Psychological Horror

Outlast
Shared: Horror · First-Person · Psychological Horror

Little Nightmares II
Shared: Adventure · Horror · Psychological Horror

SILENT HILL 2
Shared: Horror · Psychological Horror · Story Rich

Phasmophobia
Shared: Horror · Psychological Horror · First-Person

Little Nightmares
Shared: Horror · Adventure · Atmospheric

Blair Witch
Shared: Adventure · Horror · Psychological Horror

Darkwood
Shared: Horror · Adventure · Psychological Horror

Sally Face - Episode One
Shared: Psychological Horror · Story Rich · Horror

OMORI
Shared: Psychological Horror · Story Rich · Horror

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

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

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

Visage
Shared: Horror · Psychological Horror · Adventure

Outer Wilds
Shared: Adventure · Story Rich · Exploration