Horrible mismanaged dev time, lack of focus, and excessive ambition.
Dev is making the same game in parallel twice. Once with koikatsu anime style art where the girls are expies. And one with 3d style honey select art where the girls are nominally original. Or at least he did until a couple updates ago where he suddenly stopped updating the anime style expies version.
Then in each of the two games, for each waifu there are a minimum of two routes. There is the harem route, and then there is the corruption/whore/slut route. The latter splits off based on whether you enable whoring (you are literally a pimp. whore your waifus out for cash) or sharing (gangbangs). If you disable both whoring and sharing then you are on "slut route" which as far as I can tell is just harem but with a focus on exhibitionism and less romance.
As the two of you keep on fucking in public and somehow not going to jail for it. But no other man touches your girls.
The side sluts are just random encounters that lead to instant sex. And are not really worth mentioning.
Dev then decided he wants more waifus so he wasted a year on procedural generation of waifus. This was naturally a collosal failure because procedural generation is trash.
So dev backtracked on that and game went back to normal.
But then dev decided he wants to let you have the option to play as a girl now... which at the moment is a demo with barely any content because it is literally a completely different game.
There is also a pregnancy module... which is in beta and is basically an official made by the dev mod you download and install seperately.
Then dev decided to let you play as a teacher because why not throw more stuff into the mix.
In short, this game is a hot mess