Games like SINNERS
Games like SINNERS include Firework, DISTRAINT: Deluxe Edition, The Witch's House MV, Tales of the Black Forest, and OMORI. We matched them by the tags players give SINNERS on Steam (RPG, Indie, Casual, Horror, and Puzzle): closest matches first, and among equally close ones the better-known games.

Firework
Shared: Indie · Horror · Puzzle

DISTRAINT: Deluxe Edition
Shared: Indie · Horror · 2D

The Witch's House MV
Shared: Horror · Indie · RPG

Tales of the Black Forest
Shared: RPG · Indie · Horror

OMORI
Shared: Indie · RPG · Pixel Graphics

Pony Island
Shared: Indie · Puzzle · Pixel Graphics

LIMBO
Shared: Indie · Puzzle · 2D

Angels of Death
Shared: Horror · RPG · Puzzle

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

Poppy Playtime
Shared: Horror · Puzzle · Indie

OneShot
Shared: Indie · Pixel Graphics · Puzzle

Zup! S
Shared: Indie · Casual · Puzzle

Ib
Shared: Indie · Horror · Pixel Graphics

Look Outside
Shared: RPG · Horror · Pixel Graphics

Vampire Survivors
Shared: Indie · Pixel Graphics · 2D

Undertale
Shared: RPG · Indie · Pixel Graphics

Little Nightmares
Shared: Horror · Indie · Puzzle

Little Nightmares II
Shared: Horror · Puzzle · Dark

Cookie Clicker
Shared: Casual · Horror · Indie

Baba Is You
Shared: Indie · Puzzle · Pixel Graphics

Pocket Mirror ~ GoldenerTraum
Shared: RPG · Horror · 2D

There Is No Game: Wrong Dimension
Shared: Indie · Puzzle · Casual

Please, Don’t Touch Anything
Shared: Indie · Puzzle · Pixel Graphics

Melvor Idle
Shared: RPG · Casual · Indie