Wow, this is super polished, with great character animations, nice thematic cohesion, and a great sense of style! The single bullet gameplay definitely fits the theme, but it can become pretty repetitive for how many times you need to hit the enemy to move onto the next phase. I would recommend either decreasing the enemy's health, or increasing the player's damage. It would also be great to add a power up system so that the player has more interesting things to do over time. But overall, great work!