Games like The Phoenix Initiative
Games like The Phoenix Initiative include SYNTHETIK: Legion Rising, Escape From Duckov, The Binding of Isaac, Brigador: Up-Armored Edition, and SYNTHETIK 2. We matched them by the tags players give The Phoenix Initiative on Steam (Twin Stick Shooter, Top-Down Shooter, Difficult, Tower Defense, and Action): closest matches first, and among equally close ones the better-known games.

SYNTHETIK: Legion Rising
Shared: Top-Down Shooter · Action · Difficult

Escape From Duckov
Shared: Top-Down Shooter · Action · Adventure

The Binding of Isaac
Shared: Difficult · Action · Procedural Generation

Brigador: Up-Armored Edition
Shared: Twin Stick Shooter · Top-Down Shooter · Action

SYNTHETIK 2
Shared: Top-Down Shooter · Twin Stick Shooter · Top-Down

RUINER
Shared: Top-Down Shooter · Action · Twin Stick Shooter

Nuclear Throne
Shared: Difficult · Top-Down Shooter · Action

HELLDIVERS™ Dive Harder Edition
Shared: Top-Down Shooter · Twin Stick Shooter · Action

Enter the Gungeon
Shared: Difficult · Twin Stick Shooter · Action Roguelike

Relic Hunters Zero: Remix
Shared: Twin Stick Shooter · Top-Down Shooter · Action

Monster Hunter: World
Shared: Action · Difficult · Character Customization

The Ascent
Shared: Top-Down Shooter · Action · Twin Stick Shooter

The Hong Kong Massacre
Shared: Action · Top-Down Shooter · Twin Stick Shooter

Lumencraft
Shared: Action · Tower Defense · Top-Down Shooter

Dead Estate
Shared: Twin Stick Shooter · Difficult · Action

X-Morph: Defense
Shared: Tower Defense · Action · Twin Stick Shooter

Teleglitch: Die More Edition
Shared: Top-Down Shooter · Difficult · Action

Halo: Spartan Assault
Shared: Top-Down Shooter · Action · Twin Stick Shooter

Galactic Glitch
Shared: Twin Stick Shooter · Top-Down Shooter · Difficult

Devil Slayer - Raksasi
Shared: Difficult · Action · Top-Down

Minishoot' Adventures
Shared: Twin Stick Shooter · Top-Down · Top-Down Shooter

Splatter - Zombiecalypse Now
Shared: Top-Down Shooter · Action · Twin Stick Shooter

Noita
Shared: Difficult · Perma Death · Action

BALL x PIT
Shared: Action · Top-Down Shooter · Top-Down