Games like The Underground Press
Games like The Underground Press include Poppy Playtime, SOMA, Outlast, What Remains of Edith Finch, and Layers of Fear (2016). We matched them by the tags players give The Underground Press on Steam (Psychological Horror, Horror, First-Person, Atmospheric, and Exploration): closest matches first, and among equally close ones the better-known games.

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

SOMA
Shared: Psychological Horror · Horror · Atmospheric

Outlast
Shared: Horror · First-Person · Psychological Horror

What Remains of Edith Finch
Shared: Atmospheric · First-Person · Exploration

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

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

Inside the Backrooms
Shared: Horror · Psychological Horror · Puzzle

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

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

Sally Face - Episode One
Shared: Psychological Horror · Horror · Puzzle

Outer Wilds
Shared: Exploration · Mystery · Atmospheric

Little Nightmares II
Shared: Horror · Psychological Horror · Atmospheric

Bendy and the Ink Machine
Shared: Horror · First-Person · Puzzle

The Room Two
Shared: Puzzle · Atmospheric · Horror

Firewatch
Shared: Atmospheric · First-Person · Mystery

Amnesia: A Machine For Pigs
Shared: Horror · Psychological Horror · Atmospheric

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

MiSide
Shared: Psychological Horror · Horror · First-Person

Little Nightmares
Shared: Horror · Atmospheric · Puzzle

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

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

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

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

Visage
Shared: Psychological Horror · Horror · First-Person