At first I was thinking the music, even if it was good, was missing something. But then you used that to have space for the music to evolve through the game, nice touch!
I also generally enjoyed the gameplay, I found myself leaning on dodging the enemies a bit more than I would have preferred but I guess that's a part of the balancing act of having a buff to the firing rate without making it totally over powered. A bit more variety in weapons, enemy types or obstacles would have been great, but in a jam you never get everything you wish for. Over all a solid jam game, you got a lot done in the time you had available.