Let's face it, it is quite simple. Those who have never played that game before should try it, as it is great with a unique sluttifing path. Those who have played it before will find much less content than before and of course will not be happy about so much time having passed and less content is playable at the moment. They / we should simply wait longer and see where it goes from here.
The new art will not keep anyone from enjoying the story. It is just a matter of taste.
From what I understood the "old" art was stolen or at least borrowed from someone else, so it is pretty obvious that the DEV had to change it with the game growing and more and more people starting to notice it.
Someone here pointed out that the new art fits to the dark setting, and I guess this could be true. On the other hand we see a great body with quite a tough and a bit scary face, too me as well this game now features one of the least appealing MCs, which of course does not make me happy with the change at all.