Greaat
I love this game... you know term "fake difficulty"?
That means game is hard because of bugs or design problems and player can't help it.
Usually, bullet hells have lot of this, and I *loved* how you avoided this.
Also, idea of progress system is great too, so everybody can play like he wants (for me, it was classical oldschool "One-Hitpoint Wonder" bullet spamming), it actually IS core feature of the game.
Proof of it's awesomeness? Bu the time of writing this review, I decided to favorite this. Really.
[off-topic] I just (among others) made you... warm an fuzzy.. *downstairs*? <cough>...
...Nevermind... ;) [/off-topic]