Having just played Kingdom Hearts I.5, jumping into Kingdom Hearts II.5 feels like gradual steps forward in terms of gameplay, but also like massive steps backwards in terms of story.
Kingdom Hearts II.5 makes the worlds of this game much larger in comparison, while also making them far more manageable. Compared to the Aladdin and Pinocchio-themed worlds of the last game, Kingdom Hearts II.5 figures out a way to simplify these worlds, and make the player feel more like they're exploring the worlds of these films, rather than throwing them into labyrinthian worlds that just follow the films note-by-note.
Kingdom Hearts II.5 takes advantage of this by allowing the game to tell its own stories, or explore what the actual worlds can be. For example, a computer in the game becomes a way to explore the world of Tron, Steamboat Willie-era Disney becomes a wonderful setting that feels like a breath of fresh air, and the then-success of Disney's live-action films allows for Pirates of the Caribbean to be thrown in with animated fare. Even when revisiting worlds from the first game, Kingdom Hearts II.5 finds a way to revitalize them or improve upon them in strong ways every time.
But with these great new worlds comes an even more convoluted story than the first time. The introduction of Organization XIII and Nobodies only confuses these ideas in a way that seems like a way to drag out this conceit into a second game. It's also never entirely clear what visiting all these Disney worlds has to do with the overarching story of Kingdom Hearts II.5 either, and especially when the game asks you to revisit each of these worlds, it does feel like busy work before continuing the actual story.
I said this in my review of Kingdom Hearts I.5 as well, but in hindsight, I almost think the collaboration with Square Enix might've been a bad thing. The Final Fantasy characters this type around are completely useless and don't seem to matter within the larger story anymore. Characters from Final Fantasy X-II come in for no other reason than to remind people that that game had just come out. And I just don't understand why this game didn't feature Mickey trying to go into these worlds and solve this story himself. This especially feels true in this game, considering how often the Kairi and Riku story in sidelined and how much more obnoxious Sora becomes in this game. But it's almost as if the Square side of things is where all the faults of this game come to light, and while it must've seemed like a promising idea back in the early 2000s, it's already starting to stretch thin a few years after the original. I'll be very curious to see just how much Final Fantasy material is included in Kingdom Hearts III, considering there haven't been many iconic characters added to that series since the mid-2000s.
But I think the overall problem with Kingdom Hearts II.5 - and probably Kingdom Hearts in general - is just a lack of clarity. The story is just awful and even the characters involved don't seem to understand or care too much about what's happening. I also feel like these games need to be clearer in the actual training of the player in this game. This could very well be my own ignorance, but I always struggled with blocking, and wished for more of the reversal tactic from the first game. But throughout this game, I felt like my plan of attack was almost always to just hack, slash and run away. This left action feeling completely boring and uneventful. I also felt like there were integral parts of fighting that I just wasn't getting because the game didn't seem to do a good job making sure I could get it. I'd rather have obnoxious tutorials that I could skip than go into the game without any real idea of how I'm supposed to fight. Especially for an RPG aimed primarily at kids, the action should've been much easier to grasp.
Overall, revisiting the worlds of Kingdom Hearts II over a decade and a half after its original release is a much less frustrating journey than trying to replay the first game. The Disney material plays extremely well in this sequel and those Disney worlds truly do feel like the player is getting to experience these worlds firsthand. But the Square side, with muddled action, a downright idiotic story and ridiculous choices still makes this a hard game to get through.