Wow, this is awesome - great job!
It's so incredibly stylish, with so many cool looking shaders, and post process effects too. Pretty much everything about the presentation is great, even the sound effects are satisfying. Sometimes lining up jumps in 3D games can be really difficult, but that shadow is in just the right place to make that work.
I'm not quite sure what happened, but my music seemed to distort a bit at the start? It also distorted when I was completing missions, and I couldn't quite tell why that was.
Having the missions is really cool, is there a way to make it so that it doesn't pause the game when you beat one? Feels like it really breaks the flow of the game needing to go over to my mouse and click on the okay button.
I used the overworld theme from Cadance of Hyrule, and it worked pretty well! (I did fall through the floor once or twice)
Overall, lots of really cool things going on here! I love when games make the music part of the gameplay, especially when you can pick any music you want and it still works. Keep it up! :D