Games like Sweezy Gunner
Games like Sweezy Gunner include Star Saviors, Bit Blaster XL, Nova Drift, Sky Force Reloaded, and BALL x PIT. We matched them by the tags players give Sweezy Gunner on Steam (Action, Indie, Bullet Hell, Space, and Shooter): closest matches first, and among equally close ones the better-known games.

Star Saviors
Shared: Action · Bullet Hell · Indie

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

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

Sky Force Reloaded
Shared: Bullet Hell · Shoot 'Em Up · Action

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

ZeroRanger
Shared: Indie · Bullet Hell · Action

LUFTRAUSERS
Shared: Indie · Bullet Hell · Action

Beat Hazard
Shared: Bullet Hell · Shoot 'Em Up · Indie

Revolution Ace
Shared: Action · Indie · Bullet Hell

Ikaruga
Shared: Bullet Hell · Action · Shoot 'Em Up

Nuclear Throne
Shared: Indie · Action · Bullet Hell

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

DoDonPachi Resurrection
Shared: Bullet Hell · Shoot 'Em Up · Action

Touhou Kouryudou ~ Unconnected Marketeers.
Shared: Action · Bullet Hell · Shoot 'Em Up

Touhou Koumakyou: New Classic - the Embodiment of Scarlet Devil
Shared: Bullet Hell · Action · Shoot 'Em Up

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

Cyberhunt
Shared: Action · Indie · Shoot 'Em Up

Touhou Juuouen 〜 Unfinished Dream of All Living Ghost.
Shared: Action · Bullet Hell · Shoot 'Em Up

DRAINUS
Shared: Action · Indie · Shoot 'Em Up

Star of Providence
Shared: Bullet Hell · Indie · Action

KovaaK's
Shared: Action · Indie · Shooter

My Friend Pedro
Shared: Action · Indie · Shooter

BLUE REVOLVER
Shared: Indie · Bullet Hell · Action

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