Lately most of the things coming out feel like some copy paste mashed fruit puree. No matter where it comes from, whether it's holywood, anime, europe, india, most cinematic entertainment is like a cushion you fall on but it won't leave you with much of anything the morning after, except dim impression of having slept. There are a few nice deeper stories trying to divine what it means to think about thinking or what Chekhov's gun could be, mainly by taking a scalpel to it instead of using mainstream superpowers to turn it on its head. Actually understanding what lies under the concept without the needto turn it into a zombie contagion is for me the culprit of a good cinema.
I like to enjoy what I watch, i like to be surprised, I like when I find myself repeating some of the lines characters say.
Now, I would not consider this a media masterpiece but given the time and place, if you watch anime, this is something different.
The characters are not perfect, the story isn't either and don't make me start about some symbology, but there's a lot I don't understand, there's a lot that I didn't expect and there are times I genuinely think what I just saw was cool.
What you can read in other comments, soundtrack, animation, reasonably good character writing - all of that true and reason enough to watch it on its own, but it does not cover the true allure of the show.
And it is a show that tells a story maximizing its media potential while diverting from conventional paths.