frankly i believe this game was well ranking. compare to their previous titles. this game have more scenes but the story really make less sense. the model and character seem like rip off from other assets with some minor twist. in fact, i believe the game play is extremely boring (from someone who keep grinding in their previous titles just to humilate Bob).
for NTR rpg? yes it better than most titles but it no where close to be a good game, not to mention even their previous work couldn't surpass that 4 stars. and the best NTR rpg with the most beloved like NTR Priest not even get 5 stars. so this game should be less. i may give it a 4 cause it was a complete games with well translate...while other still on going. that is if you are into NTR rpg. If you want NTR VN then there're tons from JP that is out league this one.
even NTR RPG there's also quite a list of good games on dlsites. you just need to look for it.
I can only really compare with things that have full on, proper translations. If they only have MTL or nothing at all, I can't really compare them, unless they're so obviously awful in every way that it doesn't matter.
Also, I wouldn't compare and RPG game like this one with a classic VN. The story-telling overall is extremely different.
As for games in progress... I wouldn't compare with those at all. I don't believe in rating an incomplete product and I believe that the people that do so are being dumb and fucking the final rating of the game if it ever gets finished or abandoned.
In any case, I personally think that story-wise, Nebel does a lot better than a LOT of NTR stories out there. Even masterpieces out there do a lot worse jobs when it comes to giving the FMC a reason to cheat/be-raped/whatever. Kana's fears in her position are very reasonable, and Lawrence's methods are much more effective than the average NTR asshole.
Sure, the story STILL has some stupidity... but it wouldn't be NTR without it. There's no such thing as a NTR story without stupidity, it's just how NTR works. You just have to decide which forms of stupidity work for you, so to speak.