I played the demo yesterday, here are my thoughts in short.
When the main menu art started rolling in I lost my breath. Had to be looking for my jaw for some time, damn you! By this time I expected something good. And it was even better! Everything from the backgrounds to the character art and music was just perfect. The story really piqued my interest, the chibi sections were lovely and I would really dig to see them return somehow in the full game (to my understanding they're exclusive to the demo).
And I really hope you have some plans on releasing the OST, because I want it. The post-rocky soundscapes, acoustic sections are just too damn good. Very nice job.
Keep up the good work. I am sure you will.