A great idea, but terrible execution.
So why exactly does everyone love this game so much? Well the answers quite obvious really; beautiful graphics, a story and characters that everyone adored, and just the fact that you got to play through your favourite disney worlds.
You see when ever anyone praises this game the first thing they talk about is the story.
A normal kid, that wants to see the world, get's sucked into a world of classic disney and final fantasy characters, and has to fight off the heartless to save his friends Riku and Kairi. It's really quite cliche if you think about it, and it hit home with its audience perfectly. Someone normal getting sucked into a different, better, world, becoming "the chosen one" (or in this case the keyblade wielder), and having to save his friend and love interest while traveling through incredibly cool worlds and meeting their favourite characters that would fight along side them. The people playing wanted to be Sora and live out his amazing fantasy adventure.
"Ok that's great, everyone loves the story, we get it, but what about the gameplay?"
Yes what about the gameplay? Well it must be fantastic, I mean people wouldn't just like this game because of the story right?
Well... No.
Unfortunately the gameplay is not fantastic, in fact, it's barely even tolerable in my opinion. Boring repetitive combat, a terrible magic system, awkward platforming, failed rpg elements, and the worst **** camera in existence. Half of my memories of this game were me getting frustrated at it.
The camera is the main flaw in the game, and it could have been fixed so easily. I can never see where I'm going, especially during the platforming, and some of the time the camera just goes behind walls so I can't see anything at all. If this was fixed the game would be so, so much better. However it still wouldn't be a very good game. The combat system is incredibly repetitive, and hard to use. All you do is press X over and over again, but it still doesn't hit your enemies half the time. The magic never works, and half the time I heal myself in battle I get hit while I'm doing it. Also you can't even access the menu while your fighting. Your teammates are ok, however you can't decide how they attack so they end up using all there magic, never avoiding hits, and dieing in two minutes. You have to grind and level up so much, to even have a chance at beating the bosses, which takes forever and is boring as hell. Kingdom hearts is more of a chore than it a game, whenever I play it I feel like I'm being forced to do something I hate, even though I'm just being an idiot and trying to understand why everyone loves this game so much. There are no redeeming qualities for this game.
And even if you love the story, it would just be better to watch the cutscenes on Youtube than actually play the game.