Games like Square!
Games like Square! include Vampire Survivors, Megabonk, BALL x PIT, Halls of Torment, and Death Must Die. We matched them by the tags players give Square! on Steam (Action Roguelike, Bullet Hell, Action, Casual, and Roguelite): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Action Roguelike · Bullet Hell · Roguelite

Megabonk
Shared: Action Roguelike · Bullet Hell · Roguelite

BALL x PIT
Shared: Action · Bullet Hell · Roguelite

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

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

Brotato
Shared: Bullet Hell · Action Roguelike · Roguelike

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

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

Boneraiser Minions
Shared: Action Roguelike · Bullet Hell · Roguelite

Nova Drift
Shared: Bullet Hell · Action Roguelike · Roguelite

Rocket Rats
Shared: Action Roguelike · Bullet Hell · Casual

Nuclear Throne
Shared: Action Roguelike · Bullet Hell · Roguelike

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

Realm of the Mad God Exalt
Shared: Bullet Hell · Action Roguelike · Roguelike

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

Hades
Shared: Action Roguelike · Roguelite · Action

20 Minutes Till Dawn
Shared: Action Roguelike · Bullet Hell · Roguelite

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

Dungreed
Shared: Action Roguelike · Action · Roguelite

Atomicrops
Shared: Action · Bullet Hell · Action Roguelike

Soulstone Survivors
Shared: Action Roguelike · Bullet Hell · Roguelite

Dead Cells
Shared: Action Roguelike · Roguelike · Roguelite

Astro Prospector
Shared: Action Roguelike · Casual · Bullet Hell

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