Kinda insane, not in an entirely bad way. Difficulty is way up and I had to bomb all but a couple of spell cards. The game gives you a ton of life to compensate, and it's not like its so bullshit you can't do anything, so it kinda works.
I quite liked the stage sections where clearing a big enemy would clean up the screen, it felt like the enemies had just enough health to make it scary, but not actually difficult. Reminds me a bit of PoFV where you are desperately dodging until you can get the next screen clear in.
Even the popcorn fill the screen with bullets, so knowing where things spawn and killing things quickly makes a huge difference during the stage sections.