loved this game.my suggestion would be to give the game a proper ending.perhaps you can add another harder option to fight miku .if you can beat her here then the ending sequence will happen.
you could also add other fights.maybe a mode where you can't attack and only can survive and it could work as a high score system for how long you could survive.
perhaps a fight against an alternate teto who is hypnotized.where you can be sv teto.
well i love the game and it has a lot of potential but i would love it if you gave an ending to this game and make another new similiar one.
it could be a fighting game about fighting vocaloids and others perhaps.
well either way i loved your game and will play anything you publish next.