Games like Sinister Entity
Games like Sinister Entity include Poppy Playtime, Five Nights at Freddy's: Security Breach, Outlast, Escape the Backrooms, and Murder House. We matched them by the tags players give Sinister Entity on Steam (Adventure, 3D, 1980s, Demons, and Horror): closest matches first, and among equally close ones the better-known games.

Poppy Playtime
Shared: Horror · Singleplayer · Survival Horror

Five Nights at Freddy's: Security Breach
Shared: Horror · Survival Horror · 3D

Outlast
Shared: Horror · Survival Horror · Adventure

Escape the Backrooms
Shared: Horror · Adventure · Survival Horror

Murder House
Shared: 1980s · Horror · 3D

The Beast Inside
Shared: Adventure · Horror · Survival Horror

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

Granny
Shared: Horror · Survival Horror · Adventure

Outlast 2
Shared: Horror · Survival Horror · Singleplayer

The Mortuary Assistant
Shared: Horror · Demons · Mystery

The Forest
Shared: Adventure · Horror · Survival Horror

Resident Evil Village
Shared: Horror · Survival Horror · Singleplayer

Resident Evil Requiem
Shared: Horror · Survival Horror · Adventure

Inside the Backrooms
Shared: Horror · Adventure · Survival Horror

Resident Evil 2
Shared: Horror · Survival Horror · Singleplayer

Firewatch
Shared: Adventure · Mystery · Singleplayer

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

Little Nightmares
Shared: Adventure · Horror · Singleplayer

Choo-Choo Charles
Shared: Horror · Survival Horror · 3D

Home Sweet Home
Shared: Adventure · Horror · Survival Horror

Garten of Banban
Shared: Horror · 3D · Singleplayer

The Evil Within 2
Shared: Horror · Survival Horror · Adventure

Granny: Chapter Two
Shared: Adventure · Horror · Indie

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