One of the last PS2 games, and certainly one of the best.
Game play: 9/10
The game play was nearly perfect for me; I liked the occasional platforming, and the fast paced action. The only downfall for me with the game play was the random battles, but at least they took place in real time, in a way similar to Kingdom Hearts.
The mini-game "Insectron" was what really kept me hooked for the whole one hundred and eleven or so hours I played. It is a fun little side thing (For lack of a better word) that is similar to chess. You have five insectors (little bugs that you capture) on a board against an enemy's five. You choose which insector you want to be king, and defend him while trying to take out the other team's king. That's pretty much the gist of it.
Controls: 9/10
The controls are damn near perfect, and are easy to get used to. Like I said before, this game is very similar to Kingdom Hearts in many ways. You jump with X, and slash with O, which ought to sound familiar if you have played KH.
Replayability: Not Really/ 10
What I mean is that by the time you're done, you most likely won't want to replay it, unless you just completely missed out on weapons you could have got earlier or something. I actually replayed it, but that was because I didn't do insectron until much later.
Depth: 10/10
This game has so many weapons; it's not even really possible to get them all. Jaster (Main Character) has around five hundred weapons (Don't quote me on this; I'm not completely sure of the exact number). There are another few characters that you can take along in your party that have a lot of weapons as well. With the insectron, there are eight levels of bugs and over ten species. Not A LOT but this isn't pokemon, you know?
Story: [Serious Business]/ 10
This game takes itself WAY too seriously at times. It's definitely not a deal breaker, but it gets annoying when there is a sad cut scene and then an ability where someone farts into a sock and throws it at enemies (Don't ask, you'll find out). It still has a good story regardless in my opinion.
All in All: 8/10
With few problems and plenty of depth, this game is definitely worth the twenty bucks it goes for nowadays. Go pick it up if you can, but if you can't, rent it. Definitely worth every penny.