The Music and UI are really really cute xD I love those 2D animations! I got stuck on a platform and can't advanced anymore but I'm really enjoying the platforming mechanics! I also couldn't click the quit button for some reason....
But overall the feel of the game is absolutely awesome!! It felt very smooth to play. One recommendation I have might be to have a post-processing effect and lighting effect for your environment so that it blends better with character art. I love those 2D sprites and the 3D assets would love to get it even more stylized!!
(Not to mention in 3D)!