I also stopped playing Project Sekai a long time ago. I started on the JP version fairly soon after it was released. While initially I liked the story and most of the human characters, the game started to feel boring after a while. Personally I appreciated the rhythm game part of it, but the stories somehow got boring and I gradually lost interest altogether. Guess I'm just not a visual novel enjoyer. After about a year or so I stopped playing regularly (at around the same time I started playing Azur Lane, which tends to take most of the time I have in a day to play games, so in the end I just stopped logging in to ProSeka altogether). Of course my experiences are from two years ago, I have little idea what has happened in game in terms of events/stories, so I don't know if I enjoyed it more if I went back to ProSeka now, but at least for now I'm not planning to.