Games like CosmoDreamer
Games like CosmoDreamer include BALL x PIT, Sky Force Reloaded, DoDonPachi Resurrection, Escape From Duckov, and Planes, Bullets and Vodka. We matched them by the tags players give CosmoDreamer on Steam (Bullet Hell, Action, Top-Down Shooter, Shooter, and 2D Platformer): closest matches first, and among equally close ones the better-known games.
BALL x PIT
Shared: Action · Bullet Hell · Top-Down Shooter
Sky Force Reloaded
Shared: Bullet Hell · Top-Down Shooter · Action
DoDonPachi Resurrection
Shared: Bullet Hell · Top-Down Shooter · Shooter
Escape From Duckov
Shared: Action · Top-Down Shooter · Shooter
Planes, Bullets and Vodka
Shared: Action · Bullet Hell · Shooter
Touhou Koumakyou: New Classic - the Embodiment of Scarlet Devil
Shared: Bullet Hell · Action · Shoot 'Em Up
Touhou Kouryudou ~ Unconnected Marketeers.
Shared: Bullet Hell · Action · Shooter
Bit Blaster XL
Shared: Bullet Hell · Shooter · Action
Like Dreamer
Shared: Action · Bullet Hell · Shooter
Revolution Ace
Shared: Action · Bullet Hell · Shooter
Minishoot' Adventures
Shared: Bullet Hell · Cute · Top-Down Shooter
Nova Drift
Shared: Bullet Hell · Shooter · Shoot 'Em Up
Chippy
Shared: Bullet Hell · Top-Down Shooter · Shooter
ESCHATOS
Shared: Bullet Hell · Top-Down Shooter · Shooter
Vampire Survivors
Shared: Bullet Hell · 2D · Action
Crimzon Clover World EXplosion
Shared: Action · Bullet Hell · Shooter
Mirage Feathers
Shared: Bullet Hell · Cute · Shooter
12 is Better Than 6
Shared: Action · Shooter · Top-Down Shooter
LUFTRAUSERS
Shared: Bullet Hell · Action · 2D
Exit the Gungeon
Shared: Action · Bullet Hell · 2D
永远消失的幻想乡 ～ The Disappearing of Gensokyo
Shared: Bullet Hell · Action · Cute
Rocket Rats
Shared: Bullet Hell · Action · 2D
Touhou Juuouen 〜 Unfinished Dream of All Living Ghost.
Shared: Action · Bullet Hell · Shooter
Nuclear Throne
Shared: Bullet Hell · Action · Top-Down Shooter