All of the disparate pieces here, are really high quality, but i don't think they mesh very well in the end? I think some of the design decisions here mesh for a kind of sleepy gameplay experience, Enemies fire so many bullets that by the boss waves, i physically can't hit them as their shots are blocking my shots, and my hitbox is so big that dodging those patterns is a lost cause anyway. You end up just running from shield pickup to shield pickup hoping to get 1 or 2 missiles to squeak through every 10-20 seconds, which makes your boss waves really drag. I think i was on that last wave for 5-10 whole minutes haha, it also says on your page i can 'shrink time and space' but i pressed every button on controller and keyboard and couldn't find any such ability, so some extra tutorialization either in game or on the itch page might help players be a bit less confused.
I only say this kind of outright critique cause i think you've got the skills here to deliver, the visuals are top notch, the sound design is well done (maybe a less sleepy track next time tho), and the actual gameplay elements that make it up are interesting arcadey fun (missle upgrades and health pickups are a great addition to any shmup in my opinion). I know a lot of it is external packs but there's nothing wrong with that, you've put together a cohesive product with many disparate parts and that's difficult to do as a solo dev. I want to see your next game very badly c: