The upgrades didn't seem to work correctly. I didn't receive the upgrade I actually chose sometimes. Also I could shoot through walls, idk if that's intended, but it felt unfair. Also the music didn't seem to loop correctly, I got jump scared several times while playing, cause it started randomly.
Now to the good points. The music was actually awesome, and pretty cool to slay slimes to. I would have liked some actual game sounds, but the music was enough to get me hyped. The attack sprites was pretty well made, especially the shuriken. The movement also felt pretty solid. Good job.