Games like BSG: Big Space Guns
Games like BSG: Big Space Guns include Enter the Gungeon, The Binding of Isaac: Rebirth, Vampire Survivors, Nuclear Throne, and Risk of Rain (2013). We matched them by the tags players give BSG: Big Space Guns on Steam (Bullet Hell, Action Roguelike, Difficult, Roguelike, and Pixel Graphics): closest matches first, and among equally close ones the better-known games.

Enter the Gungeon
Shared: Bullet Hell · Action Roguelike · Roguelike

The Binding of Isaac: Rebirth
Shared: Action Roguelike · Roguelike · Difficult

Vampire Survivors
Shared: Bullet Hell · Action Roguelike · Pixel Graphics

Nuclear Throne
Shared: Action Roguelike · Roguelike · Bullet Hell

Risk of Rain (2013)
Shared: Action Roguelike · Roguelike · Indie

Risk of Rain 2
Shared: Action Roguelike · Co-op · Roguelike

Ravenswatch
Shared: Action Roguelike · Co-op · Roguelike

Brotato
Shared: Bullet Hell · Action Roguelike · Roguelike

Skul: The Hero Slayer
Shared: Action Roguelike · Indie · Roguelike

The Binding of Isaac
Shared: Action Roguelike · Roguelike · Difficult

Hero Siege
Shared: Action Roguelike · Pixel Graphics · Co-op

Star of Providence
Shared: Bullet Hell · Action Roguelike · Pixel Graphics

Megabonk
Shared: Action Roguelike · Bullet Hell · Roguelike

Gatekeeper
Shared: Co-op · Bullet Hell · Roguelike

Cuphead
Shared: Difficult · Co-op · Bullet Hell

Gunfire Reborn
Shared: Roguelike · Co-op · Action Roguelike

Rabbit and Steel
Shared: Bullet Hell · Co-op · Action Roguelike

Returnal™
Shared: Bullet Hell · Roguelike · Co-op

Dungreed
Shared: Action Roguelike · Roguelike · Pixel Graphics

Noita
Shared: Roguelike · Difficult · Pixel Graphics

Halls of Torment
Shared: Action Roguelike · Bullet Hell · Pixel Graphics

SYNTHETIK: Legion Rising
Shared: Action Roguelike · Indie · Difficult

Dead Estate
Shared: Action Roguelike · Roguelike · Bullet Hell

Roboquest
Shared: Action Roguelike · Co-op · Bullet Hell