Games like Gunstorm
Games like Gunstorm include Nova Drift, SNKRX, BALL x PIT, Chippy, and Sky Force Reloaded. We matched them by the tags players give Gunstorm on Steam (Arena Shooter, Top-Down Shooter, 1980s, Shooter, and Arcade): closest matches first, and among equally close ones the better-known games.

Nova Drift
Shared: Arena Shooter · Shoot 'Em Up · Arcade

SNKRX
Shared: Arena Shooter · Top-Down Shooter · Shoot 'Em Up

BALL x PIT
Shared: Arcade · Top-Down Shooter · Shoot 'Em Up

Chippy
Shared: Arena Shooter · Top-Down Shooter · Shoot 'Em Up

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

Shotgun Witch
Shared: Arena Shooter · Top-Down Shooter · Shooter

Deep Rock Galactic: Survivor
Shared: Top-Down Shooter · Arena Shooter · Top-Down

Sektori
Shared: Arena Shooter · Arcade · Shoot 'Em Up

Impact Point
Shared: Top-Down Shooter · Arena Shooter · 2D

Bit Blaster XL
Shared: Shooter · Shoot 'Em Up · Arcade

State of Anarchy: Master of Mayhem
Shared: Top-Down Shooter · Arena Shooter · Shooter

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

Deployment
Shared: Arena Shooter · Top-Down Shooter · Shooter

OMFG: One Million Fatal Guns
Shared: Arena Shooter · Arcade · Shooter

Bot Vice
Shared: Top-Down Shooter · Shoot 'Em Up · Arcade

Titan Attacks!
Shared: Arena Shooter · Top-Down Shooter · Shoot 'Em Up

Planes, Bullets and Vodka
Shared: Shoot 'Em Up · Arcade · Shooter

Hotline Miami
Shared: 1980s · Top-Down · Action

Zombieville USA 3D
Shared: Top-Down Shooter · Arcade · Shooter

Cyberhunt
Shared: Shoot 'Em Up · Arcade · Action

Kill The Crows
Shared: Top-Down Shooter · Arcade · Arena Shooter

12 is Better Than 6
Shared: Top-Down Shooter · Shooter · Action

Revolution Ace
Shared: Shoot 'Em Up · Shooter · Arcade

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