Talking about what the game is actually about (Or rather the hentai part of it). It's basically a collect photos simulator.
Since the author didn't pay the artist or even worked with him to make the game (or at least that's what it seems), he just took the images from the internet (twitter, rule34, etc) and made an rpg with it. As you can expect those type of images don't really mesh together to make actual scenes like in a normal hentai game. What the author did to "solve" it was to make the MC go around getting "photos" of the different girls instead of actually fucking them.
So yeah, while all the art is from the same artist there are no real scenes except one or two (when the author managed to get an actual set of images) and it's usually with whatever protagonists the artist put in the original picture (Like Rinko from Gundam and his son Sei).
Also the time mechanic is awful and the dialogues need work. Still...better than I was expecting (Which was your typical shitty rpg with stolen pictures from google images).
PD: Take in mind that I don't know if the art is stolen or not, only that the author isn't the artist. For all that I know the author could have asked for permission from the artist and got the "Okay". What is 100% sure is that he's not selling the game (at the moment it's free at itch.io) and that he referenced the artist and even put a link to the artist patreon (the only patreon link at that). So the author shouldn't be getting any money out of this.