Games like Let Me Out
Games like Let Me Out include Poppy Playtime, SOMA, Inside the Backrooms, Sally Face - Episode One, and Layers of Fear (2016). We matched them by the tags players give Let Me Out on Steam (Horror, Psychological Horror, Adventure, Singleplayer, and Survival Horror): closest matches first, and among equally close ones the better-known games.

Poppy Playtime
Shared: Horror · Singleplayer · Psychological Horror

SOMA
Shared: Horror · Psychological Horror · Survival Horror

Inside the Backrooms
Shared: Horror · Psychological Horror · Survival Horror

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

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

Little Nightmares II
Shared: Horror · Adventure · Singleplayer

Escape the Backrooms
Shared: Horror · Psychological Horror · Survival Horror

Garten of Banban
Shared: Horror · Psychological Horror · Singleplayer

Firewatch
Shared: Adventure · Walking Simulator · Singleplayer

Little Nightmares
Shared: Horror · Adventure · Singleplayer

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

Outer Wilds
Shared: Adventure · Mystery · Singleplayer

MiSide
Shared: Psychological Horror · Horror · Singleplayer

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

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

SILENT HILL 2
Shared: Horror · Psychological Horror · Survival Horror

Bendy and the Ink Machine
Shared: Horror · Singleplayer · Puzzle

Outlast
Shared: Horror · Psychological Horror · Survival Horror

Garten of Banban 2
Shared: Horror · Singleplayer · Psychological Horror

Resident Evil 7 Biohazard
Shared: Horror · Survival Horror · Singleplayer

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

Fran Bow
Shared: Psychological Horror · Horror · Adventure

The Beast Inside
Shared: Horror · Adventure · Survival Horror

Visage
Shared: Horror · Psychological Horror · Survival Horror