Games like Sisters Royale: Five Sisters Under Fire
Games like Sisters Royale: Five Sisters Under Fire include BALL x PIT, Vampire Survivors, LUFTRAUSERS, Sky Force Reloaded, and Exit the Gungeon. We matched them by the tags players give Sisters Royale: Five Sisters Under Fire on Steam (Bullet Hell, Top-Down Shooter, Action, Singleplayer, and Arcade): closest matches first, and among equally close ones the better-known games.

BALL x PIT
Shared: Action · Bullet Hell · Arcade

Vampire Survivors
Shared: Bullet Hell · 2D · Singleplayer

LUFTRAUSERS
Shared: Bullet Hell · Action · Arcade

Sky Force Reloaded
Shared: Bullet Hell · Top-Down Shooter · Arcade

Exit the Gungeon
Shared: Action · Bullet Hell · Arcade

Touhou Fuujinroku ~ Mountain of Faith.
Shared: Bullet Hell · Action · Indie

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

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

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

DoDonPachi Resurrection
Shared: Top-Down Shooter · Bullet Hell · Arcade

DRAINUS
Shared: Action · Singleplayer · Bullet Hell

Cyberhunt
Shared: Action · Indie · Arcade

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

Planes, Bullets and Vodka
Shared: Action · Bullet Hell · Arcade

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

Windowkill
Shared: Action · Bullet Hell · Indie

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

Mushihimesama
Shared: Bullet Hell · Action · Arcade

Brotato
Shared: Bullet Hell · Singleplayer · Top-Down Shooter

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

ZeroRanger
Shared: Bullet Hell · Action · Indie

Touhou Kouryudou ~ Unconnected Marketeers.
Shared: Bullet Hell · Action · Singleplayer

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

UBERMOSH Vol.5
Shared: Action · Arcade · Bullet Hell