KH3 is bad. If I wanted to rank the main games, it'd be KH2, KH1 Remastered, KH1 with the original terrible camera and platforming, and then KH3. It's not functionally broken, but it's such a disappointment.

The story is a hot mess because you need to play Birth By Sleep to know who Aqua is, and KH 0.2 to figure out how she got to KH3, Dream Drop Distance to know how Sora and Riku got there (which also builds off KH:coded) and to understand why you're fighting Organization XIII again after you defeated them entirely in 2 and why there's multiple versions of the big bad, and KH X (the Greek letter pronounced "key") to know what the hell a random thing that shows up toward the end of the game is. And I'm probably forgetting stuff. I hadn't played everything, and by the end, I was just sitting back and saying "Yeah, that's another thing that didn't make any sense" for about every story point.

The attractions have no place in combat. They make it insanely easy, and I decided to turn them off entirely after I beat a boss just by juggling it on a pendulum ride. The Disney worlds kind of feel bare bones despite their size. It's pretty, but it's also empty.

I wanted to love this game so, so much, but they had to cover over a decade of lore because the creator couldn't finish FFXV, and it's not brought together in any really coherent or satisfying way. The combat managed to be a step down from KH2. I finished the game, and I was just frustrated because it just was not good.

All that said, for buying it, this game is supposed to tie up all the endings started in the other games. I'd just grab 1.5+2.5, and you'll still have a good chunk of content if you've only played the main games. But if you also want to grab 2.8, buying the bundle is just cheaper.