Games like NinjaFall
Games like NinjaFall include Brawlhalla, Your Only Move Is HUSTLE, Mark of the Ninja, NINJA GAIDEN: Ragebound, and Anomaly Agent. We matched them by the tags players give NinjaFall on Steam (Ninja, 2D Fighter, Side Scroller, 2D Platformer, and Tutorial): closest matches first, and among equally close ones the better-known games.

Brawlhalla
Shared: 2D Fighter · 2D Platformer · Platformer

Your Only Move Is HUSTLE
Shared: 2D Fighter · Action · Side Scroller

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

NINJA GAIDEN: Ragebound
Shared: Ninja · 2D Platformer · Action

Anomaly Agent
Shared: Side Scroller · 2D Platformer · 2D Fighter

Mark of the Ninja: Remastered
Shared: Ninja · Side Scroller · Action

Broforce
Shared: Action · Platformer · 2D

Pizza Tower
Shared: 2D Platformer · Platformer · Cartoony

The Messenger
Shared: Ninja · Platformer · 2D

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

Rivals of Aether
Shared: 2D Fighter · Platformer · PvP

Katana ZERO
Shared: Action · 2D Platformer · Platformer

JoJo's Bizarre Adventure: All-Star Battle R
Shared: PvP · 2D Fighter · Action

SANABI
Shared: 2D Platformer · Action · 2D

Shovel Knight: Treasure Trove
Shared: Platformer · 2D · Side Scroller

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

20XX
Shared: Platformer · 2D Platformer · Action

DRAGON BALL FighterZ
Shared: 2D Fighter · Action · PvP

SHINOBI: Art of Vengeance
Shared: 2D Platformer · Ninja · Action

BlazBlue Entropy Effect
Shared: Action · 2D · Platformer

Gravity Circuit
Shared: Platformer · Action · 2D Platformer

Sonic Mania
Shared: Platformer · 2D · Side Scroller

GUILTY GEAR -STRIVE-
Shared: 2D Fighter · PvP · Anime

ROUNDS
Shared: 2D Fighter · PvP · Action