Bullet Witch is a third-person shooter where players control the witch Alicia and her unseen companion "Darkness" while navigating a three-dimensional post-apocalyptic world. The game's six levels are divided into semi-open environments, ranging from urban to country settings. Environments include destructible objects and combustibles that generate explosions when damaged. At the beginning of each level Alicia is assigned a variety of abilities and weapon attributes. Alicia has a health meter and magic meter, both of which automatically regenerate over time. Restorative items to speed up regeneration can also be received from non-playable characters (NPCs) Alicia saves from attack.
Combat is primarily based around using Alicia's "gun rod" weapon and magic abilities against normal enemies and during scripted boss battles. While Alicia mainly fights alone, she is joined by NPCs for later major battles. Her gun rod transforms into multiple types of guns, each with different ammunition types, firing rates and damage. When the game starts Alicia only has access to the rod's machine gun mode, but skill points acquired after completing levels can be used to unlock shotgun, canon, and Gatling gun modes. Reloading after a magazine is exhausted costs Alicia magic points. Each gun type can be augmented with additional functions or deal higher damage by using magic. Alicia can also perform a melee attack when close to enemies.