Games like Gulls of Doom
Games like Gulls of Doom include Vampire Survivors, BALL x PIT, Nuclear Throne, Brotato, and Enter the Gungeon. We matched them by the tags players give Gulls of Doom on Steam (Action, Roguelike, Bullet Hell, Roguelite, and Top-Down Shooter): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Bullet Hell · Roguelite · Roguelike

BALL x PIT
Shared: Action · Roguelite · Bullet Hell

Nuclear Throne
Shared: Roguelike · Action · Bullet Hell

Brotato
Shared: Roguelike · Bullet Hell · Roguelite

Enter the Gungeon
Shared: Bullet Hell · Roguelike · Action

Megabonk
Shared: Roguelike · Roguelite · Bullet Hell

Halls of Torment
Shared: Bullet Hell · Roguelite · Roguelike

Skul: The Hero Slayer
Shared: Action · Roguelike · Roguelite

Hades
Shared: Roguelite · Action · Roguelike

Noobs Want to Live
Shared: Roguelike · Bullet Hell · Action

Tiny Rogues
Shared: Bullet Hell · Top-Down Shooter · Roguelite

SYNTHETIK: Legion Rising
Shared: Action · Roguelite · Top-Down Shooter

Hades II
Shared: Action · Roguelike · Roguelite

Death Must Die
Shared: Bullet Hell · Roguelite · Action

Deep Rock Galactic: Survivor
Shared: Roguelite · Bullet Hell · Top-Down Shooter

The Binding of Isaac
Shared: Roguelike · Action · Indie

Tower of Babel: Survivors of Chaos
Shared: Bullet Hell · Roguelike · Roguelite

The Spell Brigade
Shared: Bullet Hell · Roguelite · Roguelike

Dungreed
Shared: Roguelike · Action · Roguelite

Star of Providence
Shared: Bullet Hell · Roguelite · Action

I Am Legion: Stand Survivors
Shared: Bullet Hell · Roguelite · Roguelike

Pathogenic
Shared: Roguelike · Bullet Hell · Top-Down Shooter

Voidigo
Shared: Roguelike · Bullet Hell · Roguelite

Magicraft
Shared: Bullet Hell · Roguelite · Roguelike