The game has good bones to it. You can see the general intentions for characters and their basic story lines, and the general intended gameplay is there. But the thing with good bones, is that they're just that. Good bones. There's still a whole lot more work to be done on improving those bones.
To start with, the UI. It's bad. Real bad. To get from home to work takes three mouse clicks, then another click to choose to work, then another click to choose how long you want to work, and then yet another click if you roll the co-worker event. 6 mouse clicks total. It doesn't sound like much, but having to do that every day of the working week gets old fast. And that's just going to work, since going home is another three clicks assuming you don't go elsewhere first.
A map system would be a good way to cull the clicking, but getting rid of choosing how long to do something would also help too, since those options don't really add anything, and there's no real reason why studying can't just be a flat one or two hours, nor why working can't just be a flat, eight hours too.
Additionally, having to click on an interact button, then clicking on the girl you want to interact with, then on the interact option you want, only to then have to click on what sub-option you want is needlessly convoluted too. Cull it, it adds nothing. Personally, I'd have a list of the girls that can be interacted with in the bottom bar somewhere, and have the player either click on the girl in the bar, or the girl themselves, to interact with them. I'd also get rid of the menu system too, and strip it back to have just 'catch-up', 'flirt', 'touch/grope', 'sex', and the 'special' option.
Also, the game doesn't have a point to interacting with a girl more than once a day, since gains from interactions or specials are restricted to once a day. This is arbitrary, and only serves to pad out the gameplay with no tangible benefit for the players experience. My advice is to separate a day to morning, evening, and maybe even night, with gains possible once per time period.
Building on that point, I'd like to pivot into the masseuse skill, since that too suffers from painful content stretching. It'd be fine if you could train it more than once a day, but even then the player has no tangible way to tell how many times they need to train. My advice is to cut training to a flat three repeats, with dialogue hints to make clear what stage the players at. Doing that way would also allow you to keep it a trained-once-per-day skill without trying the players patience.
Finally, it took me til the end of content in version 1.1 for me to notice that the touch option became viable, allowing me to increase corruption without buying UP. That's an issue. It needs to be better flagged, although the fact touching unlocked before flirting did is the much bigger issue imo. Either way, increasing corruption shouldn't be smashing my head into a wall, and it really needs streamlining. The same goes for the Phone menu. Unless they're able to memorise names, a player has to flick through every girl's stats to find the one they want. This could be easily solved by adding a small pic of the girls faces next to their names. You could even make it more immersive/seamless by trying to emulate an actual phones contact screen.
In all honesty, my advice to the dev right now is to not work on any new content. The game doesn't need new content right now. What the game does need, is serious work on improving the player's experience of what's already there. As I've said before, the bones of the game are good. Real good. You just need to work on refining and improving the player's experience, like the ungodly amount of clicking, before building on it.