I don't understand some people's anger. At this point, there is only a handful original games on here. Mostly it's a guy with 2 sisters, one cute and clingy, the other older and angry. He has usually a horny aunt and he meets horny girls. It's like hundreds of these games on this site, a lot of them high profile ones. So what that this is another one of those.
Now, that being said. I wasn't a big fan of the school part. At one point the characters tell you they moved from everyone they knew with no way to contact them again, but suddenly in the school, the MC knows everyone.
I think, the dev should review this part and make it more consistent. Ruby is fine by me. I took it as an omage to Summertime Saga. But I think, that the dev should make it more "meta" and acknowledge the inspiration, so it doesn't look like plagiarism... and maybe a bit more organic instead of "I like you, and I want you... now give me a handjob."
Btw, the ntr haters swarming every thread should really go to therapy. Those guys look for it everywhere even if it's not there at all. Who cares about some VN? It's not like you have invested hundreds of hours or cash into the game. I don't want to act like some guru, but when I see a game with NTR, I just skip it, that's all you need to do.