Games like Zerion-X9
Games like Zerion-X9 include Sky Force Reloaded, Vampire Survivors, Halo: Spartan Assault, KovaaK's, and Project Wingman. We matched them by the tags players give Zerion-X9 on Steam (Action, Top-Down Shooter, 2.5D, Indie, and Futuristic): closest matches first, and among equally close ones the better-known games.
Sky Force Reloaded
Shared: Top-Down Shooter · Action · Bullet Hell
Vampire Survivors
Shared: Bullet Hell · Indie · Singleplayer
Halo: Spartan Assault
Shared: Action · Top-Down Shooter · Singleplayer
KovaaK's
Shared: Action · Indie · Shooter
Project Wingman
Shared: Action · Indie · Singleplayer
Bright Memory: Infinite
Shared: Action · Indie · Singleplayer
BALL x PIT
Shared: Action · Top-Down Shooter · Bullet Hell
My Friend Pedro
Shared: Action · Indie · Shooter
Titanfall® 2
Shared: Action · Singleplayer · Futuristic
12 is Better Than 6
Shared: Action · Top-Down Shooter · Indie
RUINER
Shared: Action · Top-Down Shooter · Indie
UBERMOSH Vol.5
Shared: Action · Indie · Top-Down Shooter
Call of Duty®: Black Ops III
Shared: Action · Singleplayer · Futuristic
Bit Blaster XL
Shared: Action · Bullet Hell · Controller
LUFTRAUSERS
Shared: Action · Indie · Bullet Hell
Brotato
Shared: Singleplayer · Bullet Hell · Indie
Yet Another Zombie Survivors
Shared: Top-Down Shooter · Indie · Singleplayer
Megabonk
Shared: Indie · Action · Bullet Hell
Exit the Gungeon
Shared: Action · Indie · Arcade
MULLET MADJACK
Shared: Action · Indie · Singleplayer
KILL KNIGHT
Shared: Top-Down Shooter · Bullet Hell · Indie
SYNTHETIK: Legion Rising
Shared: Top-Down Shooter · Action · Indie
The Ascent
Shared: Top-Down Shooter · Action · Indie
X-Morph: Defense
Shared: Action · Indie · Top-Down Shooter