Great work!
I like the take on the theme, I like the atmosphere with the music and the kind of material design :)
So design is super cool! Great
The gameplay lacks of some actions, everything is a bit too slow, some enemies' patterns take too much. I like the powerups idea as well, you could have put some offensive powerups in the early stage. :)
Anyway it's a 5/5 entry from a design-side. Bravo