Games like Ninja Survivor
Games like Ninja Survivor include Vampire Survivors, Halls of Torment, BALL x PIT, Windowkill, and Megabonk. We matched them by the tags players give Ninja Survivor on Steam (Action, Action Roguelike, Bullet Hell, Arcade, and 2D): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Action Roguelike · Bullet Hell · 2D

Halls of Torment
Shared: Action Roguelike · Bullet Hell · Action

BALL x PIT
Shared: Action · Bullet Hell · Arcade

Windowkill
Shared: Action · Action Roguelike · Bullet Hell

Megabonk
Shared: Action Roguelike · Bullet Hell · Action

Death Must Die
Shared: Action Roguelike · Bullet Hell · Action

Seraph's Last Stand
Shared: Action Roguelike · Bullet Hell · 2D

Boneraiser Minions
Shared: Action Roguelike · Bullet Hell · 2D

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

Enter the Gungeon
Shared: Action Roguelike · Bullet Hell · Action

Nova Drift
Shared: Bullet Hell · Action Roguelike · Arcade

Spirit Hunters: Infinite Horde
Shared: Action Roguelike · Action · Bullet Hell

Rogue: Genesia
Shared: Action Roguelike · Bullet Hell · Arcade

Crab Champions
Shared: Action Roguelike · Arcade · Bullet Hell

Deep Rock Galactic: Survivor
Shared: Action Roguelike · Bullet Hell · Action

The Binding of Isaac
Shared: Action Roguelike · Action · Dark

The Binding of Isaac: Rebirth
Shared: Action Roguelike · 2D · Indie

Rabbit and Steel
Shared: Action Roguelike · Bullet Hell · 2D

A Dance of Fire and Ice
Shared: 2D · Arcade · Action

Exit the Gungeon
Shared: Action · Arcade · Bullet Hell

LUFTRAUSERS
Shared: Bullet Hell · Action · Arcade

Rogue Legacy
Shared: Action Roguelike · Action · 2D

Risk of Rain Returns
Shared: Action Roguelike · 2D · Action

Desktop Survivors 98
Shared: Action Roguelike · Action · Bullet Hell