Excellent game.
Very well-made. I especially liked the graze bar, combined with the masses of later-level enemies that shoot beams at you that can be dodged oh-so-easily for some much-needed life powerups.
For a sequel, or other similar games, have you considered procedurally generating the enemy paths and shot patterns? 'd be interesting to see what happens when danmaku stops being predictable (as in, you can no longer memorize a level and get through it that way).