The year is 2013, and the world has been overrun by an army of evil monsters. The military has been fighting a losing battle against these demons, and humanity has begun to give up hope. Suddenly, a woman with a huge gun shaped like a broom appears, and journeys to face off against these demons for herself...

Bullet Witch is a third-person shooter. In it, players control Alicia, the titular Bullet Witch, who wields a broom-shaped gun (called a "Gunrod") that can also be used to cast magic. In addition to this, the Gunrod can also transform into different gun types, such as a shotgun and gatling gun.

Alicia makes her way through various stages, fighting hoardes of demons with the Gunrod and her magic. Magic can be used to create magic walls to protect from enemy fire, summon a flock of ravens to attack foes, sacrifice her own blood to save innocents, amongst other talents. After completing a level, Alicia earns skill points, which can be alotted to various skills to upgrade them.