Games like Charles Haunted Mansion
Games like Charles Haunted Mansion include Firewatch, Look Outside, Outlast, Five Nights at Freddy's: Into the Pit, and SOMA. We matched them by the tags players give Charles Haunted Mansion on Steam (Horror, Adventure, Walking Simulator, Singleplayer, and Casual): closest matches first, and among equally close ones the better-known games.

Firewatch
Shared: Adventure · Walking Simulator · Singleplayer

Look Outside
Shared: Horror · Pixel Graphics · Adventure

Outlast
Shared: Horror · Survival Horror · Singleplayer

Five Nights at Freddy's: Into the Pit
Shared: Horror · Adventure · Pixel Graphics

SOMA
Shared: Horror · Survival Horror · Atmospheric

DAVE THE DIVER
Shared: Adventure · Pixel Graphics · Casual

Little Nightmares
Shared: Horror · Adventure · Singleplayer

DISTRAINT: Deluxe Edition
Shared: Horror · Adventure · Pixel Graphics

Poppy Playtime
Shared: Horror · Singleplayer · Survival Horror

The Forest
Shared: Horror · Adventure · Survival Horror

Layers of Fear (2016)
Shared: Horror · Walking Simulator · Singleplayer

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

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

Visage
Shared: Horror · Survival Horror · Singleplayer

Mad Father
Shared: Horror · Pixel Graphics · Adventure

Little Nightmares II
Shared: Horror · Adventure · Singleplayer

Darkwood
Shared: Horror · Adventure · Survival Horror

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

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

The Beast Inside
Shared: Horror · Adventure · Singleplayer

Among the Sleep - Enhanced Edition
Shared: Horror · Adventure · Singleplayer

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

Outlast 2
Shared: Horror · Singleplayer · Survival Horror

Still Wakes the Deep
Shared: Horror · Walking Simulator · Adventure