Games like Alastrius: Star-Fighter
Games like Alastrius: Star-Fighter include Nex Machina, Greedland, Beat Hazard, CYGNI: All Guns Blazing, and Waves. We matched them by the tags players give Alastrius: Star-Fighter on Steam (On-Rails Shooter, Twin Stick Shooter, Shoot 'Em Up, Bullet Hell, and Space Sim): closest matches first, and among equally close ones the better-known games.

Nex Machina
Shared: Twin Stick Shooter · Bullet Hell · Shoot 'Em Up

Greedland
Shared: Shoot 'Em Up · Twin Stick Shooter · Bullet Hell

Beat Hazard
Shared: Twin Stick Shooter · Bullet Hell · Shoot 'Em Up

CYGNI: All Guns Blazing
Shared: On-Rails Shooter · Bullet Hell · Shoot 'Em Up

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

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

Dimension Tripper Neptune: TOP NEP
Shared: On-Rails Shooter · Bullet Hell · Shoot 'Em Up

Ex-Zodiac
Shared: On-Rails Shooter · Shoot 'Em Up · Flight

Cyberhunt
Shared: Shoot 'Em Up · Twin Stick Shooter · Action

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

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

Mirage Feathers
Shared: On-Rails Shooter · Bullet Hell · Shoot 'Em Up

Cleared Hot
Shared: Flight · Vehicular Combat · Twin Stick Shooter

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

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

Sky Force Reloaded
Shared: Shoot 'Em Up · Bullet Hell · Arcade

Geometry Wars™ 3: Dimensions Evolved
Shared: Twin Stick Shooter · Shoot 'Em Up · Bullet Hell

STAR WARS™: Squadrons
Shared: Flight · Singleplayer · Action

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

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

Geometry Wars: Retro Evolved
Shared: Twin Stick Shooter · Bullet Hell · Shoot 'Em Up

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

Jet Lancer
Shared: Shoot 'Em Up · Flight · Action

Whisker Squadron: Survivor
Shared: On-Rails Shooter · Shoot 'Em Up · Bullet Hell