It does get hard fast, sorry if you thought it was a bit too much, I definitely could have made the difficulty ramp slower.
I do think it gets easier if you try to limit yourself to one bullet until at least loop 5, and try to kill the monsters (the first enemy) each loop because they won't despawn at the end of the loop, making them multiply really quickly.
That's just some tips that should make the game less hard, in case you want to give it another try :)
Thank you for the kind words!