Okay, first off, this is really well-made. Great job on it so far. I have a few minor complaints, though.
1. Balance for some attacks is pretty off. For example, Remilia's level 2 charge attack (and 3 too, I think) goes way too fast for being such a large bullet - it either completely misses you, or it flies right into you with no warning whatsoever and no chance to dodge. A lot of level 4 attacks are too strong, to the point where they're even hard to dodge on their own - remember that the players have to go through randomly-placed bullets in addition to all the boss attacks! I'm not going to go through every example unless you want me to, but I would like to say one, which deserves its own number:
2. Lily White! It's even harder to dodge her barrage than it was in the original, so tone down the speed and density a bit.
3. It might just be me, but the very small bullets (the ones that are everywhere) hit me by surprise a lot more than they did in PoFV. Maybe I'm just distracted because I'm looking at the new characters, but it's worth checking out anyway - try changing the graphic to have more contrast, maybe?
4. No difficulty selection, and the AI seems wonky (they focus and unfocus about five times per second - don't stare at CPU Komachi's screen or you'll go blind). Not sure how much you can do to fix this though, since I don't know much about how you make an AI.
5. A lot of the characters' level 1 charge attacks are just powerful forward bursts. That's okay for a few characters, but half of the new ones just have some variation on that...
6. I know this happened in PoFV, but can you please make it so fairies don't spawn from the bottom corner if your character's there?
7. Very minor, but Reisen's exploding bullet of doom doesn't have the same cool wavy effect as in PoFV. I don't blame you though; that's probably hard to replicate (I copied it in Danmakufu, but I'm not sure how well it works in the program you're using for this).
That's every flaw I can find right now other than what people mentioned. Keep working on this - it's coming out amazing so far.