Wow that level of polish just blew my mind! Particles everywhere, cool effects, cool graphics, crisp controls, awesome music, awesome sound design... That's honestly impressive what you managed to do in only 7 days!
My main concern about this game is that the theme is purely "cosmetic"... At the end of each level, we interact with something that vaguely looks like a door, and that's it ^^'. Compared to similar SHMUPs, the theme only had an effect on one sprite, I would have prefered it if the theme was also in the core gameplay.
But don't get me wrong, it's still a really good game! It feels awesome to play and I had a lot of fun ^^!