Interesting concept. The fact that you could shoot enemies didn't feel as instinctual as it probably should - especially considering how the gun had been used for platforming so far, and the shurikens aren't exactly 'organic' enemies that seem to be killable. Maybe consider giving more obvious effects? Or perhaps lowering their hp to kill shurikens on one hit. It would also be great if you placed the corridor full of shurikens level as your first introduction to being able to shoot enemies so that it's more intuitive to shoot your way through, and introduce the concept to players faster.