Wow, what a great game. First off, presentation is enjoyable, with nice art & music. The procedural generation is varied & organic, & I couldn't even tell how you did it, which is a good sign. The enemy types are varied enough to where they don't get stale, but there isn't too many to learn either. Also, the boss fight at the end was very unexpected.
I noticed that whenever you transition between floors, the music bugs out. I also noticed it happen a couple times when a room was entered too. The boss fight at the end was in my opinion too difficult, as if you die to it, you have to do all 6 floors over again, which isn't very fun.
Overall, excellent job!