Hello Miari! Thank you so much for playing! It is indeed hard and also some information is not easy to read in its current rushed state. Sadly I could not make sound because I didn't manage time well, and I forgot to remove the slider, so that's confusing.
The link with the theme is weak, everytime you die or win and therefore play again, you will face a new fleet of ships. Every game a random type of inner circle, middle circle, outer circle, cardinal points and center boss ships are selected, changing the bullet patterns you will be facing. They're not a lot different with each other, so it's probably hard to notice. Also the action is pretty hectic.
I already have an update with sound and slightly better visualization of information (e.g. a danger level bar showing you when the fight is gonna levelup), a few bugfixes and some QoL improvements here and there.
I spent the vast majority of the time tinkering with the underlying system and eye candies, then I threw out something that could look like a game with what I had in the last couple days. I don't think it's a well designed game per se, but I think I learnt a lot about time management and top-down character controllers, so it was a very good experience.