Games like Castle In The Darkness
Games like Castle In The Darkness include Hollow Knight, Hollow Knight: Silksong, Shovel Knight: Treasure Trove, Celeste, and The Messenger. We matched them by the tags players give Castle In The Darkness on Steam (Metroidvania, Indie, Platformer, Action, and Difficult): closest matches first, and among equally close ones the better-known games.

Hollow Knight
Shared: Metroidvania · Platformer · Difficult

Hollow Knight: Silksong
Shared: Metroidvania · Indie · Difficult

Shovel Knight: Treasure Trove
Shared: Platformer · Indie · Pixel Graphics

Celeste
Shared: Indie · Difficult · Platformer

The Messenger
Shared: Metroidvania · Platformer · Pixel Graphics

Skul: The Hero Slayer
Shared: Indie · Action · Pixel Graphics

Dust: An Elysian Tail
Shared: Metroidvania · Platformer · Action

Axiom Verge
Shared: Metroidvania · Indie · Platformer

Blasphemous
Shared: Metroidvania · Pixel Graphics · Indie

Rogue Legacy 2
Shared: Metroidvania · Platformer · Indie

Ori and the Will of the Wisps
Shared: Metroidvania · Platformer · Action

Nine Sols
Shared: Metroidvania · Platformer · Difficult

Gato Roboto
Shared: Metroidvania · Indie · Action

SANABI
Shared: Action · Pixel Graphics · Indie

Hyper Light Drifter
Shared: Indie · Pixel Graphics · Difficult

Out There Somewhere
Shared: Platformer · Indie · Pixel Graphics

Super Meat Boy
Shared: Platformer · Indie · Difficult

Katana ZERO
Shared: Action · Pixel Graphics · Platformer

Bloodstained: Curse of the Moon
Shared: Action · Platformer · Metroidvania

Dead Cells
Shared: Metroidvania · Adventure · Pixel Graphics

Rogue Legacy
Shared: Platformer · Indie · Action

Environmental Station Alpha
Shared: Metroidvania · Indie · Platformer

Deaths Gambit: Afterlife
Shared: Metroidvania · Pixel Graphics · Action

VVVVVV
Shared: Platformer · Indie · Pixel Graphics