I wouldn't go as far as to say I didn't enjoy it, I don't think I would have stuck with it so long If I didn't at least think it had potential and there are aspects I enjoyed of course. The overall mystery was engaging, it just took too long to have any real payoffs or build up the individual murders, and while I'm usually not a fan of romance I actually found that aspect quite cute.
As for characters acting like different people, off the top of my head, There was Mikhail who spent Ch 2 acting completely different than Ch 1 he was much more confident and at times seemed aggressive and taunting while in the 1st he was much more meek. Kostya, of course, spent the second half of ch 2 trying to delude himself into thinking nothing was wrong or suspicious, despite being fairly intelligent and more level-headed when it comes to trust previously. K becoming more whiny and less competent and some others I'm forgetting but the one that convinced me that this had to be intentional was actually when you talked to Yana after you started investigating, the entire game she has been nothing but rude and dismissive of others and of murder, but when you talk to her she talks about how she understands this is difficult and that she would do her best to find the killer, it felt contrary to her portrayal until then. But these examples are just off the top of my head and I would need to re-read it to be more specific.
On their own those things would be understandable, Kostya having a mental breakdown, or Mikial becoming more comfortable, but altogether it had me convinced that Mikial had somehow used some kind of mind-altering substance on everyone or at least Kostya, which made everyone ignore his blatantly suspicious behavior or making them more dumb and docile, like right before the murder where Kostya somehow thinks he had to go to the audience hall, then follow Mikhail.
As for the morality issue, it's less of an issue than I made it sound, like I said these things are difficult to elaborate in text but I felt the perspectives were too limited, ranging from "killing murderers is a good thing" to "I agree but I don't want to watch". I could have missed something of course but that's just how It looked to me.
I apologize if my previous comments came off as rambly or insulting, I was very tired at the time and wanted to get my thoughts down fast, but wanted to keep it vague to avoid spoilers in my comment.
As I said there are aspects I liked and I still look forward to seeing what you make. I'm willing to try it again when it's Its fully complete, but currently, it just takes too long to do too little to keep me engaged.