Thank you so much for the kind words and thorough review!
I have to agree on slowing it down. Duckblade and I playtested and beat every level multiple times, but that was after hours of practice while debugging. Of course, players don't have those hours to put in. If there's one thing I could change now, it would be to add a couple of buttons on the options page to slow down projectiles by 50% and to increase the vortex's radius by 50%. Making the difficulty curve a bit gentler is ideal, but limited time and all that.