Thank you for your kind words! My whole idea when I started working on this project was "Dark Souls but 2D" (hence the name), so I'm really happy that the boss was challenging. I really enjoyed making the suprise endings so I'm happy you've found them!
Pressing Q works (at least it did during testing) it just has a bit of a wond up (0.75 seconds if memory serves me right) and you have to stand still/can't attack during that duration. I might change it after the jam is over if it feels really weak though.
Thank you for your feedback and for providing this jam for newbies like me!