Games like Seraph
Games like Seraph include Hollow Knight: Silksong, Hollow Knight, Bloodstained: Ritual of the Night, ICEY, and Skul: The Hero Slayer. We matched them by the tags players give Seraph on Steam (Action, Female Protagonist, Platformer, Side Scroller, and 2D): closest matches first, and among equally close ones the better-known games.

Hollow Knight: Silksong
Shared: Metroidvania · 2D · Great Soundtrack

Hollow Knight
Shared: Platformer · Metroidvania · 2D

Bloodstained: Ritual of the Night
Shared: Female Protagonist · Action · Metroidvania

ICEY
Shared: Action · Female Protagonist · Side Scroller

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

The Vagrant
Shared: Action · Female Protagonist · 2D

Broforce
Shared: Action · 2D · Platformer

My Friend Pedro
Shared: Action · Shooter · Indie

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

Rogue Legacy 2
Shared: Action · Platformer · Metroidvania

Rogue Legacy
Shared: Platformer · Action · 2D

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

20XX
Shared: Action · Platformer · Female Protagonist

Iconoclasts
Shared: Female Protagonist · Action · Indie

Freedom Planet
Shared: Action · Platformer · Female Protagonist

Shantae and the Pirate's Curse
Shared: Platformer · Female Protagonist · Action

Axiom Verge
Shared: Platformer · Action · Metroidvania

Celeste
Shared: Platformer · Female Protagonist · Great Soundtrack

Indivisible
Shared: Action · Female Protagonist · Platformer

Valdis Story: Abyssal City
Shared: Action · Platformer · Metroidvania

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

ENDER MAGNOLIA: Bloom in the Mist
Shared: Female Protagonist · 2D · Metroidvania

Shantae: Risky's Revenge - Director's Cut
Shared: Female Protagonist · Platformer · Action

Katana ZERO
Shared: Action · Platformer · Great Soundtrack