If you ask me, it's everything about this game, it's not trying to be cool, it is naturally freaking cool in all aspects
Let's start with my favorite, the MUSIC!!
Of all games I've ever played, this is the only one where I think all (or most of) the songs are a masterpiece, it is that good!
I swear that like half the reason I love this game so much, it's it's soundtrack, without it, the game would feel souless.
When you think you found your favorite song, then another one appears, and it is an absolute BANGER!
But, the music it's not the only reason of course
Let's talk about the characters.
At first we are introduced to a couple pretty normal characters (well, Rindo looks pretty awesome for being your average normal guy (Thanks to Tetsuya Nomura awesome fashion design), then after the story progresses, you find some iconic characters that look much better than before! You can feel they have grown as a person, since the last time you saw them (well, at least most of them, but they still have their cool, fun personality).
The antagonists are pretty good too, expect some really epic battles with them, and I also prefer the Game Master from this game, but that's just me :)
I won't talk too much about the artstyle, it is and has always been wonderful since the first game, it is unique, it is his own thing and we love it.
The story may get a bit confusing at some point, but if you played the first one (including Another Day) and you read the secret reports from both games, you should have a better idea of everything that is happening, the Secret Reports are the deeper, untold part of both games I would say, pretty similar to Kingdom Hearts secret reports.
In the end, this is a game everybody should play, even if it's just for the fantastic music or the fun gameplay alone, like trying to collect all the pins and items, the replay value is high as well.
Square Enix did a great job with this sequel, making it even better than the first one in my opinion, and I cannot thank them enough, God bless everyone involved in creating such a wonderful experience.
10/10.