5/5. This is absolutely amazing, you have both created an insanely polished product with some super engaging mechanics.
A few little bugs here and there but nothing that couldn't be compensated for once you figured out what causes them - they were easy to deal with in the game. One bug (at least I think it was a bug) that I found particularly handy was the sword doing 75 damage instead of 15 if you cancelled the spin attack before running out of mana, really helped with the boss fight! ;) The only other bug was some transitions between rooms screwed the camera up, but you could fix that by going half into a room transition trigger then turning back around.
Absolutely fantastic stuff, and I really enjoyed the soundtrack too. Some more audio and slight tweaks to the way the AI works would be the only things I would modify.