Games like Yissa Deep Realms
Games like Yissa Deep Realms include Celeste, Hollow Knight, Hollow Knight: Silksong, SANABI, and Skul: The Hero Slayer. We matched them by the tags players give Yissa Deep Realms on Steam (Platformer, Difficult, Side Scroller, Female Protagonist, and 2D): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Difficult · Platformer · Female Protagonist

Hollow Knight
Shared: Platformer · Difficult · 2D

Hollow Knight: Silksong
Shared: Difficult · Platformer · 2D

SANABI
Shared: Action · Story Rich · Pixel Graphics

Skul: The Hero Slayer
Shared: Action · Platformer · 2D

Shovel Knight: Treasure Trove
Shared: Platformer · 2D · Difficult

Katana ZERO
Shared: Platformer · Action · Story Rich

Nine Sols
Shared: Difficult · Platformer · 2D

ICEY
Shared: Female Protagonist · Action · Side Scroller

Super Meat Boy
Shared: Platformer · Difficult · 2D

Geometry Dash
Shared: Difficult · 2D · Platformer

Touhou Luna Nights
Shared: Difficult · Side Scroller · Platformer

Freedom Planet
Shared: Platformer · Female Protagonist · Action

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

Rain World
Shared: Difficult · Platformer · 2D

Bloodstained: Ritual of the Night
Shared: Female Protagonist · Action · Side Scroller

Momodora: Reverie Under The Moonlight
Shared: Side Scroller · Female Protagonist · Difficult

GRIS
Shared: Female Protagonist · Platformer · Adventure

Mark of the Ninja
Shared: Platformer · 2D · Side Scroller

Tomb Raider Game of the Year
Shared: Female Protagonist · Action · Adventure

Bloodstained: Curse of the Moon
Shared: Platformer · Action · 2D

Jump King
Shared: Difficult · Platformer · Adventure

Foregone
Shared: Platformer · Side Scroller · Action

Broforce
Shared: Platformer · Action · 2D