Games like SUBSUMED
Games like SUBSUMED include SOMA, Outlast, Firewatch, Layers of Fear (2016), and No, I'm not a Human. We matched them by the tags players give SUBSUMED on Steam (Horror, Atmospheric, Linear, Exploration, and Psychological Horror): closest matches first, and among equally close ones the better-known games.

SOMA
Shared: Horror · Atmospheric · Psychological Horror

Outlast
Shared: Horror · Atmospheric · Psychological Horror

Firewatch
Shared: Atmospheric · Adventure · Exploration

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

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

The Forest
Shared: Horror · Open World · Adventure

Five Nights at Freddy's: Security Breach
Shared: Horror · Singleplayer · Multiple Endings

Visage
Shared: Horror · Psychological Horror · Atmospheric

Subliminal
Shared: Atmospheric · Psychological Horror · Horror

Little Nightmares
Shared: Horror · Atmospheric · Singleplayer

Scanner Sombre
Shared: Horror · Exploration · Atmospheric

MiSide
Shared: Horror · Psychological Horror · Atmospheric

Darkwood
Shared: Horror · Psychological Horror · Atmospheric

Subnautica 2
Shared: Horror · Exploration · Atmospheric

Poppy Playtime
Shared: Horror · Singleplayer · Psychological Horror

Subnautica
Shared: Horror · Exploration · Singleplayer

Little Nightmares II
Shared: Horror · Atmospheric · Singleplayer

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

Outer Wilds
Shared: Exploration · Atmospheric · Adventure

Lethal Company
Shared: Horror · Exploration · Psychological Horror

SILENT HILL 2
Shared: Horror · Psychological Horror · Atmospheric

What Remains of Edith Finch
Shared: Atmospheric · Exploration · Singleplayer

DREDGE
Shared: Exploration · Atmospheric · Horror

Outlast 2
Shared: Horror · Psychological Horror · Atmospheric