Games like E.Y.E.R.I.S.
Games like E.Y.E.R.I.S. include Sky Force Reloaded, BALL x PIT, Chippy, Waves, and Nex Machina. We matched them by the tags players give E.Y.E.R.I.S. on Steam (Bullet Hell, Shoot 'Em Up, Top-Down Shooter, Twin Stick Shooter, and Choices Matter): closest matches first, and among equally close ones the better-known games.

Sky Force Reloaded
Shared: Shoot 'Em Up · Bullet Hell · Top-Down Shooter

BALL x PIT
Shared: Bullet Hell · Action · Shoot 'Em Up

Chippy
Shared: Bullet Hell · Shoot 'Em Up · Twin Stick Shooter

Waves
Shared: Bullet Hell · Shoot 'Em Up · Twin Stick Shooter

Nex Machina
Shared: Bullet Hell · Twin Stick Shooter · Action

Rogue: Genesia
Shared: Bullet Hell · Twin Stick Shooter · Choices Matter

Sektori
Shared: Shoot 'Em Up · Twin Stick Shooter · Bullet Hell

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

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

Beat Hazard
Shared: Bullet Hell · Twin Stick Shooter · Shoot 'Em Up

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

Deep Rock Galactic: Survivor
Shared: Bullet Hell · Top-Down Shooter · PvE

State of Anarchy: Master of Mayhem
Shared: Bullet Hell · Top-Down Shooter · Shoot 'Em Up

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

X Invader
Shared: Shoot 'Em Up · Bullet Hell · Twin Stick Shooter

Greedland
Shared: Shoot 'Em Up · Bullet Hell · Twin Stick Shooter

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

#KILLALLZOMBIES
Shared: Twin Stick Shooter · Action · Shoot 'Em Up

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

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

Cyberhunt
Shared: Shoot 'Em Up · Action · Twin Stick Shooter

Voidigo
Shared: Twin Stick Shooter · Bullet Hell · Shoot 'Em Up

SYNTHETIK: Legion Rising
Shared: Top-Down Shooter · Action · Twin Stick Shooter

DoDonPachi Resurrection
Shared: Shoot 'Em Up · Bullet Hell · Top-Down Shooter