Games like Wren's Resurgence
Games like Wren's Resurgence include Celeste, SANABI, Katana ZERO, Anomaly Agent, and Blasphemous 2. We matched them by the tags players give Wren's Resurgence on Steam (Side Scroller, 2D Platformer, Hack and Slash, Difficult, and Platformer): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Difficult · 2D Platformer · Platformer

SANABI
Shared: 2D Platformer · Story Rich · 2D

Katana ZERO
Shared: 2D Platformer · Platformer · Hack and Slash

Anomaly Agent
Shared: Side Scroller · 2D Platformer · Hack and Slash

Blasphemous 2
Shared: Difficult · 2D Platformer · Side Scroller

Momodora: Reverie Under The Moonlight
Shared: 2D Platformer · Side Scroller · Female Protagonist

Afterimage
Shared: 2D Platformer · Side Scroller · Female Protagonist

Touhou Luna Nights
Shared: Side Scroller · Difficult · Platformer

Super Meat Boy
Shared: Difficult · 2D Platformer · Platformer

Skul: The Hero Slayer
Shared: 2D · Platformer · Side Scroller

NINJA GAIDEN: Ragebound
Shared: 2D Platformer · Side Scroller · Platformer

Hollow Knight
Shared: Platformer · Difficult · 2D

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

Mina the Hollower
Shared: 2D Platformer · Action-Adventure · Platformer

ICEY
Shared: Side Scroller · Hack and Slash · Female Protagonist

The Messenger
Shared: Platformer · 2D Platformer · 2D

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

Foregone
Shared: Side Scroller · Platformer · 2D

BlazBlue Entropy Effect
Shared: Platformer · Action-Adventure · 2D

Divinum
Shared: Hack and Slash · 2D Platformer · Side Scroller

Nine Sols
Shared: Difficult · Platformer · 2D

The Vagrant
Shared: Side Scroller · Female Protagonist · Hack and Slash

Rain World
Shared: Difficult · Platformer · 2D Platformer

Shovel Knight: Treasure Trove
Shared: Platformer · Difficult · Side Scroller