Games like Illumina Defender
Games like Illumina Defender include Vampire Survivors, Shelldiver, LUFTRAUSERS, Oxygen Not Included, and Exit the Gungeon. We matched them by the tags players give Illumina Defender on Steam (Shooter, Strategy, Bullet Hell, Action, and Colorful): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Bullet Hell · Singleplayer · Pixel Graphics

Shelldiver
Shared: Resource Management · Arcade · Management

LUFTRAUSERS
Shared: Bullet Hell · Action · Arcade

Oxygen Not Included
Shared: Resource Management · Singleplayer · Strategy

Exit the Gungeon
Shared: Action · Bullet Hell · Arcade

ShellShock Live
Shared: Strategy · Shooter · Action

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

Bit Blaster XL
Shared: Bullet Hell · Shooter · Action

Police Stories
Shared: Strategy · Action · Shooter

Star Saviors
Shared: Bullet Hell · Action · Strategy

Freeman: Guerrilla Warfare
Shared: Strategy · Shooter · Action

BALL x PIT
Shared: Action · Bullet Hell · Arcade

The Escapists
Shared: Strategy · Singleplayer · Action

Titanfall® 2
Shared: Shooter · Action · Singleplayer

Nova Drift
Shared: Bullet Hell · Shooter · Arcade

DRAINUS
Shared: Shooter · Action · Bullet Hell

Halo: Spartan Assault
Shared: Action · Shooter · Strategy

Factorio
Shared: Strategy · Resource Management · Management

ZeroRanger
Shared: Bullet Hell · Action · Shooter

Enter the Gungeon
Shared: Bullet Hell · Pixel Graphics · Action

Door Kickers
Shared: Strategy · Action · Singleplayer

Broforce
Shared: Action · Shooter · Pixel Graphics

PUBG: BATTLEGROUNDS
Shared: Shooter · Action · Strategy

Call of Duty®
Shared: Shooter · Action · Singleplayer