Oh Nomura. Of course you put essential story into the VERY END of this game lol. Don't be fooled though, it is a fun rhythm game, and worth your time.
Kingdom Hearts consistently has some of the best music put to game, and the chance to enjoy that for hours on end shouldn't be overlooked. Now here's where my first gripe comes in. I liked the boss & cinematic fights much better because I loved the button holding element. I thought it was more fun, and flowed better with the rhythm of the songs. I wish it had just been that style the whole game, but it's nice you can choose that when you're just playing individual tracks.
Unironically, this is also a great refresher of the story so far. Kairi explains every game in a very digestible way, so you figure out exactly what's been going on if it's been a while since you've revisited the series.
My only other complaint is I wish the rpg elements played a bigger role in the gameplay. I really never noticed a difference between my different teams if they were different levels, and ended up just playing who I liked most (Team Days all day).