The Disney worlds are implemented at their best still, quite possibly because most of the villains were Disney. I feel like the story flowed the best because of this, even though to be honest, there were not nearly as many cutscenes as the later games. I feel like they did well with establishing rules for the universe (which they break lol) and having it feel interesting and new. Obviously the "new" feeling will be gone after the first installment, but still its nice. I also feel like Sora, Riku, Donald, and Goofy all developed well enough for main characters. In comparison to some other games in the series where people rarely change at all.
Honestly, narratively I think KH1 is just solid. A lot of "issues" come up with retcons they made for no reason later like the whole Ansem thing, or everyone not giving a diddly about keeping the world order and stay a secret anymore lol. Like people like Aladdin and Ariel still found about their secret but heck, at least they tried in KH1 lol.
Gameplay wise, it has more cons. Its a bit slower, and especially in the original release traversing the menu can be a pain, so adding reaction commands and making summon separate were welcome additions. The menus weren't as refined I suppose, and they didn't have as much work into item appearance or little things like the HUD getting more creative changes in the later games.
However, I do think the special attacks were neat, and they have never done them quite like that again. Also the summons were arguably at their most useful. Party members were also at their best, as even though their AI was honestly a little worse than KH2, their damage wasn't randomly scaled back for fake "balance" lol.
The worlds had way more platforming which was good and bad ha. Like since Sora was less mobile than later games, it made platforming a chore sometimes, but it also added depth to worlds. Like, places like Deep Jungle actually go UP instead of just forward forever like every world in KH2. You could also fall into different areas and stuff like that, which felt more natural.
I also think the puzzles and side-collection quests were done well, but KH2 FM did the latter well, too.
-It has great action-packed gameplay.
-The simplicity of the story works in it's favor. While I enjoy the convoluted-ness that comes later on, the simple (and clean) story of this game works well it has a lot of raw emotion in there during everything that happens in the endgame. Sora having to fight his possessed best friend, sacrificing himself, going through the End of the World with Destati in the background, stuff like that.
-The soundtrack was great (same with all KH games). It feels very nostalgic to me for some reason.
-The voice of Sora and Ansem SoD were better than their current ones (in my opinion. Then again Sora does have to age so I guess it's justified).
-I liked the Metroidvania feeling of returning to worlds when you're more powerful and explore new areas and such.
-Ansem SoD's final form was pretty badass. Yeah it was weird, but it really feels like you're going up against a super-powered final form, and it made me think of Castlevania for some reason.
-I didn't like how the camera was panned so close to Sora during the game. When I played KH1 right after KH2, the difference was definitely there.
-Platforming felt kinda stiff at times. It was a great idea and I hope Square would refine it for later games, but with the camera and controls it was a little awkward in this game.
[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]-Expanding on the last point it did make some of the worlds a little annoying to get through. Mostly Deep Jungle. I really didn't like that world at all. o~o It makes me happy that it didn't appear in any game after that.
[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Lol, I just used Deep Jungle as an example of something I liked ha, but I realize thats always been a divisive opinion...I still would rather have stiff platforming than flat plains forever.[/FONT]