Very enjoyable. I got ending 3, precisely the one I desired to happen, glad the game had it. I ended up loving the demon character, which I think is a 'demon' only in name and appearance.
I liked the quasi-retro design of the characters, Was the demon design inspired by the 'Vrock' from D&D? I like the pallete and sharpness of the sprites, but I think the demon should have a bigger eye design so its eye-shifting anymation is more noticeable.
I felt echoes of your previous work 'I'll Come See You' on this one.
The music selection is great. A few more sound effects here and there would improve the reading experience. No flaws to point out in the backgrounds/CGs. It would be great if the whole novel could have been done with drawn backgrounds.
I'm looking foward to see more VNs from Cryoslight. I have nothing but respect for a fellow Dev who does things solo, including the art.
And a shout out for having individual versions of the game for both Win, Mac, and Linux. That is the way to do it, IMHO.