This is very fun, but hard! It's really polished too! I really like the game and though I played a lot of bullet hells, but never saw anything like this before. Sadly died quite a few times somewhere in the middle of the second (pink) level and never got to see the boss. Everything is so quick at that point usually I just got comboed to death during a single wave. Maybe everything is happening too fast and it's just very difficult to react in time? idk.
For some criticism, I'd say during the last part of the first level, I never have thought I need to hit all four edges in the first place, and just kept on banging on the centre block. It wasn't until later when I started to read that info page that I needed to do that. Probably need some text or clarification in that regard. Also, why the background music is so quiet? I know it's there but it's just poorly mastered, and will certainly get overpowered by the strong sound effects.
Anyway, I like this very much, and you should be proud of building this wonderful game! Well done!