Games like Alpha Star
Games like Alpha Star include Vampire Survivors, BALL x PIT, Nova Drift, Deep Rock Galactic: Survivor, and Rogue: Genesia. We matched them by the tags players give Alpha Star on Steam (Action, Arcade, Roguelite, Bullet Hell, and Space): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Roguelite · Bullet Hell · 2D

BALL x PIT
Shared: Action · Arcade · Roguelite

Nova Drift
Shared: Roguelite · Arcade · Bullet Hell

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

Rogue: Genesia
Shared: Bullet Hell · Roguelite · Arcade

Halls of Torment
Shared: Roguelite · Bullet Hell · Action

EVERSPACE™
Shared: Action · Space · Roguelite

Megabonk
Shared: Roguelite · Bullet Hell · Action

Jump Space
Shared: Space · Roguelite · Action

Bit Blaster XL
Shared: Bullet Hell · Arcade · Action

Windowkill
Shared: Action · Arcade · Bullet Hell

Star Saviors
Shared: Action · Bullet Hell · Arcade

Rogue Legacy 2
Shared: Arcade · Action · Roguelite

LUFTRAUSERS
Shared: Arcade · Action · Bullet Hell

Blast-off
Shared: Action · Arcade · Space

Risk of Rain Returns
Shared: 2D · Action · Sci-fi

Starship Troopers: Extermination
Shared: Action · Sci-fi · Arcade

Boneraiser Minions
Shared: Bullet Hell · Roguelite · 2D

Project Wingman
Shared: Action · Arcade · Flight

Death Must Die
Shared: Roguelite · Bullet Hell · Action

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

Exit the Gungeon
Shared: Arcade · Action · Bullet Hell

HELLDIVERS™ 2
Shared: Action · PvE · Sci-fi

Soulstone Survivors
Shared: Roguelite · Bullet Hell · Action