Games like Sad Satan
Games like Sad Satan include Outlast, MiSide, Poppy Playtime, Outlast 2, and Slender: The Arrival. We matched them by the tags players give Sad Satan on Steam (Indie, Psychological Horror, First-Person, 3D Platformer, and Walking Simulator): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: First-Person · Psychological Horror · Atmospheric

MiSide
Shared: Psychological Horror · First-Person · Singleplayer

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

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

Slender: The Arrival
Shared: Indie · First-Person · Psychological Horror

The Beast Inside
Shared: First-Person · Psychological Horror · Indie

Firewatch
Shared: Walking Simulator · First-Person · Atmospheric

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

Five Nights at Freddy's
Shared: Psychological Horror · Indie · Singleplayer

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

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

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

The Long Dark
Shared: First-Person · Singleplayer · Survival

Escape the Backrooms
Shared: Psychological Horror · First-Person · Survival Horror

We Happy Few
Shared: Indie · First-Person · Psychological Horror

The Beginner's Guide
Shared: Indie · Walking Simulator · First-Person

Blair Witch
Shared: Psychological Horror · Indie · First-Person

Among the Sleep - Enhanced Edition
Shared: Indie · First-Person · Atmospheric

The Hat Man: Shadow Ward
Shared: Indie · First-Person · Singleplayer

Resident Evil Village
Shared: First-Person · Singleplayer · Survival Horror

Visage
Shared: Psychological Horror · First-Person · Indie

From The Darkness
Shared: Psychological Horror · Indie · First-Person

Five Nights at Freddy's 2
Shared: Psychological Horror · Singleplayer · Indie

POOLS
Shared: Psychological Horror · Walking Simulator · First-Person