Firstly, Kagura now translated this game so the reviews probably overstate how bad this game is.
Also, although you can go through a whole game without rape content, this game features it heavily. Some of it is more of a trainer or corruption route but a lot is just rape.
But overall this game is a creative masterpiece.
You can't look at any one part of the game because truthfully, everything is a bit half baked on its own. CGs are really high quality but there are few. Gameplay is shallow, not exactly breaking the mold. Story is about a guy abducting a girl and training her, you've probably seen or played one of these before.
It's about how it comes together. There's 3 phases of the game. First phase is pre-abduction, which is the first unique element. A short day cycle system will have you running around town trying to do some tasks to get with/abduct this girl, while establishing that you, the MC, are a loser, and the girl is more or less the innocent, morally strong character.
If she is abducted, the game enters the second phase, where the game mainly turns into a trainer to sexually break her and a bit of world exploration to flesh out her corruption. I would class the third phase as when she is totally broken, or an ending occurs (there are many endings, this is a branching game for sure).
This is an amazing game because of the first phase combined with the other two though. The first phase is so light in tone, almost a 'slice of life' feel to it, with undertones of the MCs psychotic nature hinted at. By phase 2 and 3, you really explore the depth of the MCs depravity and the complete shift in the girl's outlook.
The game succeeds at something few games do: it creates these two characters and develops them through the events of the game and your choices, in a compelling way that made me actually play out multiple endings instead of installing the full save.
Also, this game has a great implementation of pregnancy. Really well done art on this, browning nipples, variations in the sex scenes that are involved, just great.