Okay so I've not finished the game (only one route so far, so, yeah...), and it's definitely awesome.
I often mourn the lack of enough interactivity in many simulation vn, so I've been keeping an eye on your game for a while and I'm extremely glad you could make it ! The characters, even the minor ones are all interesting and I personally found the quest system on point. Every interaction was engaging, and the art made it all better ahah.
Regarding the difficulty I found it pretty much normal actually ? It was nice to have a balance between some auditions I could breeze through stat-wise, and some where I had to work for a little. It prevents the learning system from becoming useless too soon even if at end you mostly roll with the punches (or maybe that's just me, I tend to save-scum a lot in stat-raising games at the beggining so it sure helps with getting ahead).
And because of that last habit, my end-game was a bit empty on events and quests despite the sheer number of them. So I'm probably biased, but on future projects (because I sure hope you will envisage to create more at some point !) maybe it would be beneficial to have a date-locked requirement on quests to keep a bit of harmony in the repartition of quantity ? But that's just the only (subjective) fault I could find in all this awesomeness.
I think people may find the game more punishing than what it really is either due to a lack of familiarity with these type of games or a guide/walkthrough to deal with all the information. The majority of sim games out there are a tad more demanding than this one.
So in short, thank you for this game, your reactivity regarding the bugs, not abandoning this project, and all the hard work you put into it. It shows. Please take care of yourself and enjoy the aftermath of your efforts.
I'm off to Shuu's route now !