The writing is captivating, the story seems unique and I'm looking forward to seeing more. However, I wish we could've seen at least a glimpse of the characters... I think it'd be cool if they were at least introduced in demo.
But even so, I still enjoyed the demo a lot. And art, omg... The art is just gorgeous. That's probably what captivated me the most in this demo and I'm so looking forward to the update (or full version).