Try to restart or somethin like that, my friends tested when i finished and this bug wasnt, and i dindt update the game, but can be the bullets you have 30 bullets and when you reach to 0 you need to press the right button in the mouse to put more
also if you use game maker, you can tell what could be happening, i dindt launch the open source yet but you can use like undertale mod tool that functions for all game maker games
