Games like MadMan
Games like MadMan include Outlast, Poppy Playtime, Outlast 2, Resident Evil 7 Biohazard, and Resident Evil Village. We matched them by the tags players give MadMan on Steam (Horror, First-Person, Survival Horror, Atmospheric, and Artificial Intelligence): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: Horror · First-Person · Survival Horror

Poppy Playtime
Shared: Horror · First-Person · Singleplayer

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

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

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

SOMA
Shared: Horror · Atmospheric · Psychological Horror

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

Five Nights at Freddy's: Security Breach
Shared: Horror · Survival Horror · First-Person

The Outlast Trials
Shared: Horror · Survival Horror · First-Person

Alien: Isolation
Shared: Horror · Survival Horror · Atmospheric

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

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

Little Nightmares
Shared: Horror · Atmospheric · Singleplayer

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

Visage
Shared: Horror · Survival Horror · First-Person

Dead by Daylight
Shared: Horror · Survival Horror · Gore

METRO 2033 Redux
Shared: Horror · Atmospheric · First-Person

Bendy and the Dark Revival
Shared: Horror · First-Person · Survival Horror

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

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

Little Nightmares II
Shared: Horror · Singleplayer · Atmospheric

The Beast Inside
Shared: Horror · First-Person · Survival Horror

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

Amnesia: The Bunker
Shared: Horror · Survival Horror · Atmospheric