Games like ProtoCorgi
Games like ProtoCorgi include Vampire Survivors, LUFTRAUSERS, Montaro, Bit Blaster XL, and Rabi-Ribi. We matched them by the tags players give ProtoCorgi on Steam (Bullet Time, Dogs, 2D, Bullet Hell, and Cute): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Bullet Hell · 2D · Pixel Graphics

LUFTRAUSERS
Shared: Bullet Hell · 2D · Arcade

Montaro
Shared: Cute · Dogs · Anime

Bit Blaster XL
Shared: Bullet Hell · 2D · Arcade

Rabi-Ribi
Shared: Bullet Hell · Anime · Cute

Exit the Gungeon
Shared: Arcade · Bullet Hell · 2D

SUPER CHICKEN JUMPER
Shared: 2D · Arcade · Cute

Mirage Feathers
Shared: Cute · Bullet Hell · Anime

Neptunia Shooter
Shared: Bullet Hell · Cute · Anime

Planes, Bullets and Vodka
Shared: Bullet Hell · 2D · Arcade

Last Command
Shared: Bullet Hell · 2D · Cute

ZeroRanger
Shared: Bullet Hell · 2D · Arcade

BALL x PIT
Shared: Bullet Hell · Arcade · 2D

DRAINUS
Shared: 2D · Bullet Hell · Action

Touhou Tenkuushou ~ Hidden Star in Four Seasons.
Shared: Bullet Hell · Cute · 2D

QP Shooting - Dangerous!!
Shared: Bullet Hell · Arcade · Cute

Touhou Hero of Ice Fairy
Shared: Bullet Hell · Anime · Cute

DJMAX RESPECT V
Shared: Cute · Anime · 2D

Muse Dash
Shared: Cute · Anime · 2D

Touhou Koumakyou: New Classic - the Embodiment of Scarlet Devil
Shared: Bullet Hell · 2D · Cute

Broforce
Shared: 2D · Pixel Graphics · Action

Undertale
Shared: 2D · Pixel Graphics · Singleplayer

Enter the Gungeon
Shared: Bullet Hell · Pixel Graphics · 2D

Hatsune Miku: Project DIVA Mega Mix+
Shared: Cute · Arcade · Anime