Games like The Nightwatch
Games like The Nightwatch include Vampire Survivors, Halls of Torment, Death Must Die, Megabonk, and Soulstone Survivors. We matched them by the tags players give The Nightwatch on Steam (Bullet Heaven, Action Roguelike, Bullet Hell, Roguelike, and Twin Stick Shooter): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Action Roguelike · Bullet Hell · Roguelite

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

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

Megabonk
Shared: Bullet Heaven · Action Roguelike · Roguelike

Soulstone Survivors
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

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

Brotato
Shared: Roguelike · Bullet Hell · Action Roguelike

BALL x PIT
Shared: Bullet Hell · Action Roguelike · Roguelike

Boneraiser Minions
Shared: Action Roguelike · Bullet Hell · Bullet Heaven

Nordic Ashes: Survivors of Ragnarok
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

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

Nova Drift
Shared: Bullet Hell · Action Roguelike · Bullet Heaven

Tower of Babel: Survivors of Chaos
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

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

Yet Another Zombie Survivors
Shared: Bullet Heaven · Action Roguelike · Roguelite

Time Wasters
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

The Spell Brigade
Shared: Bullet Heaven · Bullet Hell · Action Roguelike

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

Atomicrops
Shared: Bullet Hell · Roguelike · Action Roguelike

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

Astro Prospector
Shared: Roguelike · Action Roguelike · Bullet Heaven

Nuclear Throne
Shared: Action Roguelike · Roguelike · Bullet Hell

Hades
Shared: Action Roguelike · Roguelite · Roguelike