Games like Space Invaders Extreme
Games like Space Invaders Extreme include Bit Blaster XL, Planes, Bullets and Vodka, Nova Drift, Ikaruga, and BALL x PIT. We matched them by the tags players give Space Invaders Extreme on Steam (Shoot 'Em Up, Bullet Hell, Arcade, Action, and Shooter): closest matches first, and among equally close ones the better-known games.

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

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

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

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

BALL x PIT
Shared: Action · Arcade · Bullet Hell

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

LUFTRAUSERS
Shared: Bullet Hell · Arcade · Action

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

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

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

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

DoDonPachi Resurrection
Shared: Shoot 'Em Up · Bullet Hell · Arcade

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

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

Jets'n'Guns Gold
Shared: Shoot 'Em Up · Action · Bullet Hell

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

Vampire Survivors
Shared: Bullet Hell · 2D · Arcade

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

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

DRAINUS
Shared: Shoot 'Em Up · Action · Shooter

Exit the Gungeon
Shared: Arcade · Action · Bullet Hell

Touhou Kinjoukyou ~ Fossilized Wonders.
Shared: Shoot 'Em Up · Bullet Hell · Action

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

Touhou Kouryudou ~ Unconnected Marketeers.
Shared: Shoot 'Em Up · Bullet Hell · Action