Just finished the game! It was great! I love how polished the art is and the 8 bit music remixes fits very well. The controls are responsive, I especially love the slide jump tech on Noel.
I did not notice any bugs. I was stuck on several places (aqua candles, endless running, true end), though its satisfying once I figure it out.
The early platforming section in the final stage was hard, I felt like the axes were impossible to dodge sometimes.
On everything else, the difficulty is just right for me! I was beating most bosses with around 20% hp left, while some of the harder bosses took 2-3 tries. Though note that I am a more experienced gamer, so mileage may vary.
Overall I loved the game! There are lots of cool bosses, and the gameplay changes up from time to time so I was never bored.
Looking forward to your next work!