WatTime for realtalk.
The level design of KH1 is fantastic. Every room is densely packed and encourages exploration to find all the knick knacks scattered around the worlds. Every world is subtly distinct from each other to the light puzzle elements of Wonderland and Agrabah to the pure white knuckle brawling of Olympus and Neverland to the swimming in Atlantica (which is good just use magic instead of whacking away aagh) to the sprawling halls of Hollow Bastion. They feel like actual worlds to explore, each carrying a strong visual identity, a roadtrip through a multiverse of some of the most widely beloved characters in any medium.
KH1 is a genius cocktail of Mario platforming and Final Fantasy's RPG elements mixed together with Disney and just enough original elements to build its own identity, and it's a damn shame the series started toning down everything that made the first game so good in every successive release.
Like, I think the level design of Kingdom Hearts 1 is okay and way better than Kingdom Hearts 2 but... Wat.
Did you even play through shit like Deep Jungle or Monstro. Those hippos still make me want to tear my hair out.