Um where to start on this game.... All I can say is that I have critical feelings about this game.
In this role-playing game the Sora we all know and love journies through the data-scape to repair the worlds inside the journal that contain the events of the original kingdom Hearts. Few things I have to say about the gameplay. What really disapointed me in this game is that, THIS GAME IS FRIKEN SHORT!!!!! Sorry about the language. Also, this game does not get as much commands from it's counter-part Birth by Sleep. After beating the game, you could re-challenge sectors to get SP Prizes but who has that time anyways. Also you rarely get partners. A big let done from the kingdom Hearts game. The valuable thing about this game is that you get a sneak peak at Kingdom Hearts 3.
Nothing much to say about the sound, but soon you get annoyed with the music. I only like the beginning, ending (Which is sang by Utada Hikura, beautiful voice by the way) and finally the title song.
If you want to know what happens I recommend to rent the game to get a sneak peak into Kingdom Hearts 3. If you want a better hand-held Kingdom Hearts go with Birth By Sleep.