I'm a massive fan of Alphonse Mucha's art, and it's incredibly obvious that the devs are too. A lot of the fonts are straight out of Mucha's own style, and the rich and baroque circular reliefs you see on a lot of the UI is similarly extremely Mucha-esque. As an art dweeb it makes me super happy to see one of my favorite artists' styles applied so liberally and with such great effect.
And as someone that is aggressively homosexual, I'm glad to look at the pretty boys too. Only visual novel to have ever piqued my interest, and first one to ever get me to bite the bullet and buy it. Actually been waiting on it for a while. It'd be a lot of fun to read a dev blog about their art direction decisions! I'm definitely a fan. Hope to see the full game come to Android, but I'll stick with the PC variant for the time being.