Games like NinjaThea 2
Games like NinjaThea 2 include Celeste, Super Meat Boy, Downwell, VVVVVV, and Pizza Tower. We matched them by the tags players give NinjaThea 2 on Steam (Casual, Precision Platformer, 2D Platformer, Platformer, and Female Protagonist): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Precision Platformer · Pixel Graphics · Platformer

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

Downwell
Shared: Precision Platformer · Pixel Graphics · Platformer

VVVVVV
Shared: Precision Platformer · Platformer · Pixel Graphics

Pizza Tower
Shared: 2D Platformer · Platformer · Indie

SANABI
Shared: Pixel Graphics · 2D Platformer · Platformer

Katana ZERO
Shared: Pixel Graphics · Platformer · 2D Platformer

Kaze and the Wild Masks
Shared: Casual · Precision Platformer · Family Friendly

Brawlhalla
Shared: Casual · 2D Platformer · Platformer

Planet of Lana
Shared: 2D Platformer · Female Protagonist · Platformer

Thomas Was Alone
Shared: Platformer · 2D Platformer · Precision Platformer

FEZ
Shared: Platformer · Pixel Graphics · Casual

Geometry Dash
Shared: Precision Platformer · Platformer · Singleplayer

Sonic Origins
Shared: 2D Platformer · Casual · Platformer

Gensokyo Night Festival
Shared: Casual · Pixel Graphics · Indie

Assemble with Care
Shared: Casual · Indie · Female Protagonist

Webbed
Shared: 2D Platformer · Pixel Graphics · Platformer

They Bleed Pixels
Shared: Platformer · Precision Platformer · Female Protagonist

Jump King
Shared: Precision Platformer · Pixel Graphics · Platformer

Unpacking
Shared: Casual · Pixel Graphics · Singleplayer

Trine 2: Complete Story
Shared: 2D Platformer · Platformer · Casual

Ambidextro
Shared: Precision Platformer · 2D Platformer · Pixel Graphics

Kitsune Tails
Shared: Precision Platformer · Pixel Graphics · Platformer

The End Is Nigh
Shared: Precision Platformer · Platformer · Indie