Played the first Kingdom Hearts as part of that Remix collection thing. Just going to first of all say that I'm only in it for the Disney side of things and couldn't really give two shits about the FF characters. Majority of the game is great fun, with some highlights being Halloween Town, Agrabah and Monstro. The game particularly shines when it leans into the Disney. I do feel that the balance flips too far the other direction in the final third of the game. The natural endpoint for the game feels like the Hollow Bastion chapter. Really, the game should have ended there. It's suitably challenging, has a fair few decent puzzles, and it has that whole 'end game' feel down quite well. The fecking Maleficent Dragon boss was an absolute pain in the arse to fight against. Storywise, the game reaches a good conclusion in that section.
The whole last 'End of the world' chapter and everything attached to it is pure bullshit, however. Too many waves of enemies and far, far too many boss fights. It's too repetitive. The scale up in difficulty is also ridiculous. Chernabog is possibly one of the worst designed bosses I've seen in any game. It also contains too many incidents of 'stupid videogame logic'. One example of this is using magic and summoning. You are flying during this boss fight. You can cast magic whilst flying, but you can't summon. Ok...that makes no sense. To summon, you have to land somewhere and summon. The only viable way of doing this is to land on Chernabog's shoulder...which you fall through half the time. You can literally fly through the boss on many instances, which is just fecking stupid. Not only that, but the boss himself contains one particularly bullshit move where he forces flames to appear all around him, which deal a ridiculous amount of damage. After lots of cursing, I managed to get through the fight, only to find that you have 4 more boss fights before the end of the game. Some of which you have to do back to back without the option of saving.
Unfortunately, that last chapter left a huge blemish on the game for me. It's a really strange design choice and makes me question how many people actually finished the game. Questioning whether to bother with 2 and 3...and that's without even getting into the stupid amount of side-games in between the main series.