Games like Two-Fifteen
Games like Two-Fifteen include Outlast, Poppy Playtime, SOMA, Little Nightmares, and Outlast 2. We matched them by the tags players give Two-Fifteen on Steam (Horror, Singleplayer, Dark, Indie, and Psychological Horror): closest matches first, and among equally close ones the better-known games.

Outlast
Shared: Horror · Singleplayer · Psychological Horror

Poppy Playtime
Shared: Horror · Singleplayer · Dark

SOMA
Shared: Horror · Psychological Horror · Dark

Little Nightmares
Shared: Horror · Singleplayer · Dark

Outlast 2
Shared: Horror · Psychological Horror · Singleplayer

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

Escape the Backrooms
Shared: Horror · Psychological Horror · Singleplayer

Little Nightmares II
Shared: Horror · Singleplayer · Dark

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

MiSide
Shared: Horror · Psychological Horror · Singleplayer

Visage
Shared: Horror · Dark · Psychological Horror

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

Darkwood
Shared: Horror · Psychological Horror · Dark

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

Slender: The Arrival
Shared: Horror · Indie · Dark

Buckshot Roulette
Shared: Dark · Horror · Singleplayer

Garten of Banban
Shared: Horror · Singleplayer · Psychological Horror

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

Bendy and the Dark Revival
Shared: Horror · Singleplayer · Indie

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

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

IMSCARED
Shared: Horror · Indie · Psychological Horror

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

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