The sandbox actually holds this one back because it's only used to get from scene to scene and there isn't anything unique about the scenes themselves. It's just looking for people. If there were stats and jobs and whatnot that impacted what choices are available and how scenes turn out that would change things a bit.
Otherwise the only other problem I have is the blackmail. For one it's basically the only route available in game, if you play a route where you aren't blackmailing the girls or burning bridges you get almost no good content. That wouldn't be bad if the option to influence your blackmail rested on character stats. Why do I bring this up? Because as it stands the blackmail in this game is badly done. When you have a picture of the dean and a faculty member sexually involved with a student that will trump everything in a judges eyes. It's not the police who decide who goes to jail on the spot they simply investigate and they ask questions. So why is there not a scene you can unlock where you bulldog Sarah into supporting your claims before you fuck Kate? If the blackmailer were even decent at the job he would have done this to ensure that if he did end up arrested Sarah would throw Kate or Aiko under the bus getting you out. Otherwise all that info you learned about her gets leaked along with some photos. This alone would muddy the waters so much that no judge would simply say "Yeah this dude raped Kate he's guilty.". The question would become "Did this Aiko girl have fantasies and him wanting out make her do this? In this case Aiko is now the rapist."
These are actual things that will go through ANYONE'S head regardless of whether or not it's a porn game. The blackmail needs to be better done. As it stands Aiko and Kate reverse blackmail route makes no sense as you have a nuclear bomb over both of them. Yes both of them because Kate admitted that her and Aiko LOVE each other. Weak link found. One thing life should teach anyone, you cannot combat a nuclear bomb with a handgun. The photos of Aiko with other girls and Sarah proves she's into kinky shit so how would authorities assume it's black and white instead of shades of grey? If you do reverse blackmail you need to give the initial blackmailer less powerful material. You also need to give the option of going nuclear because he's already shown that he's willing to pull a gun on people. What stops him from making Kate take a load without pills when he could give Aiko a new hole in the head? The MC needs to be drastically "weakened" for the story as written to work. Otherwise it's just a self insert with meaningless choices and it's better off being a kinetic novel.
Finally the UI needs work. Why can't you click the map button from anywhere exactly? That alone would have saved a lot of clicks and time as many locations have multiple rooms like Sarah's house or the University.
Beyond the QOL stuff the only gripe I have is that the MC got a Tsar Bomba while everyone else at best has a 9mm yet he treads carefully in the most meaningless ways and doesn't use his leverage when he should.