Games like AST-Hero
Games like AST-Hero include Bit Blaster XL, Sky Force Reloaded, Ikaruga, Planes, Bullets and Vodka, and Bot Vice. We matched them by the tags players give AST-Hero on Steam (Hero Shooter, Shoot 'Em Up, Top-Down Shooter, Bullet Hell, and Difficult): closest matches first, and among equally close ones the better-known games.

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

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

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

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

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

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

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

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

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

ZeroRanger
Shared: Shoot 'Em Up · Bullet Hell · Arcade

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

Phoenix Force
Shared: Bullet Hell · Difficult · Top-Down Shooter

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

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

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

BLUE REVOLVER
Shared: Shoot 'Em Up · Bullet Hell · Arcade

UBERMOSH Vol.5
Shared: Arcade · Bullet Hell · Top-Down Shooter

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

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

Touhou Tenkuushou ~ Hidden Star in Four Seasons.
Shared: Bullet Hell · Shoot 'Em Up · Difficult

Touhou Koumakyou: New Classic - the Embodiment of Scarlet Devil
Shared: Shoot 'Em Up · Bullet Hell · Difficult

Cuphead
Shared: Difficult · Bullet Hell · Shoot 'Em Up

Crimzon Clover World EXplosion
Shared: Shoot 'Em Up · Bullet Hell · Top-Down Shooter

Super Star Path
Shared: Shoot 'Em Up · Top-Down Shooter · Bullet Hell