An amazing, fun game that is a completionist's dream.
Half its charm is its innocence; playable by children, yet still entertaining and challenging for adults. I played it to 100%, and beating Sephiroth is very difficult on hard mode (as it should be!). But for those who don't like a challenge, you can always set it to easy and go from there. But shame on you if you do. Slackers.
The storyline is great, it has nice graphics, the camera never seems to get in the way, and the music is enchanting. I could listen to the main menu music all day, and the opening song is on my MP3 player.
The only downside, Gummi Ships. Just seemed like an added mini-game that never quite meshed to me. But apart from that, it's an excellent game.
In fact, if you haven't played it, stop reading reviews and go do it!