For sound I will talk about voice acting, I enjoy the seiyuu in this game. I don't know how they worked with them but sometimes it sounds like a few of them are recording their lines in their bathroom, please give them a place to record and proper equipment Solmare they deserve it :( the character songs are also good and I think there should be more released.
Gameplay is pay to win and very grindy for materials. Unfortunately ranking in events is impossible now unless youre VIP and honestly not that worth it.
Story lines are hit and miss because in events they cater to every romanceable character so nothing progresses. In main story some scenes of your fav can be very entertaining, but options are very limited to try and appeal to as many players as possible.
Value overall is good if you are invested in the characters. You can get tickets pretty quickly for gacha as well so at least you can always be doing something in the game.