Games like Asteroidia
Games like Asteroidia include Bit Blaster XL, BALL x PIT, Planes, Bullets and Vodka, Deep Rock Galactic: Survivor, and Sky Force Reloaded. We matched them by the tags players give Asteroidia on Steam (Bullet Hell, Shoot 'Em Up, Action, Casual, and Top-Down Shooter): closest matches first, and among equally close ones the better-known games.

Bit Blaster XL
Shared: Bullet Hell · Shoot 'Em Up · Shooter

BALL x PIT
Shared: Action · Bullet Hell · Shoot 'Em Up

Planes, Bullets and Vodka
Shared: Shoot 'Em Up · Action · Casual

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

Sky Force Reloaded
Shared: Shoot 'Em Up · Bullet Hell · Top-Down Shooter

Nova Drift
Shared: Bullet Hell · Shoot 'Em Up · Arcade

20 Minutes Till Dawn
Shared: Bullet Hell · Shoot 'Em Up · Top-Down Shooter

DoDonPachi Resurrection
Shared: Shoot 'Em Up · Bullet Hell · Top-Down Shooter

HELLDIVERS™ 2
Shared: PvE · Action · Shooter

Cyberhunt
Shared: Action · Casual · Shoot 'Em Up

Crimzon Clover World EXplosion
Shared: Shoot 'Em Up · Bullet Hell · Action

Goobies
Shared: Bullet Hell · Top-Down Shooter · Casual

Ikaruga
Shared: Bullet Hell · Shoot 'Em Up · Action

Apocalypse Party
Shared: Casual · Bullet Hell · Top-Down Shooter

Revolution Ace
Shared: Shoot 'Em Up · Action · Bullet Hell

Halo: Spartan Assault
Shared: Action · Top-Down Shooter · Shooter

Star Saviors
Shared: Bullet Hell · Shoot 'Em Up · Action

State of Anarchy: Master of Mayhem
Shared: Bullet Hell · Action · Top-Down Shooter

Assault Android Cactus+
Shared: Bullet Hell · Shoot 'Em Up · Shooter

Waves
Shared: Bullet Hell · Shoot 'Em Up · Shooter

Greedland
Shared: Shoot 'Em Up · Bullet Hell · Action

ESCHATOS
Shared: Bullet Hell · Shoot 'Em Up · Top-Down Shooter

Chippy
Shared: Bullet Hell · Shoot 'Em Up · Top-Down Shooter

Nex Machina
Shared: Bullet Hell · Action · Shoot 'Em Up