KH2 is by far better. It's all the first one was and more. The story is a lot more complex than in the first one, the battle system has been vamped up to something even better with the addition of the drives and recation commands, and the gummi ship minigame might as well be a game in itself this time around. It's actually fun rather than cumbersome like it was in the first game.

Some things are a little disappointing...like not having dodge roll (probably the best action skill in the first game, though, the ability you get from one of your drives replaces it, it's still not quite as good), keyblades don't do as much for your strength stat (you could use the Kingdom Key the whole entire game if you wanted and it wouldn't really hinder you much), and I don't like the Coliseum as much this time around. Storywise it was a lot better, but the optional cups with the whole idea of the stipulations and having to level up all your drive and summon level to max to get the 50 round cup of the game is kind of tiring. Other than that, everything else is great.

People are also saying this one is harder...I'm not sure if that's true or not because to me this one seemed easier in most parts, but then there were about two really insane boss battles in the game that were harder than any of the battles that were in the first game aside from Sephiroth, and I take into consideration I played the first one about two years ago, so I'm probably just better at games now.