On its own, it's a great game. As a sequel to a classic, it disappoints. (EDITED REVIEW!)
The most noticeable difference in Chrono Cross is the art direction. The character models look fantastic, and the envoirments are nicely detailed. The decision to turn to this has given Cross a more serious tone to the series than its predecessor, which in some cases is a hit and miss. To Final Fantasy fans, this may strike them as great, but to Trigger fans, this element alone will turn them off.
The story behind Chrono Cross is actually a very compelling one, although as a Trigger fan I had myself going "huh?". It seems as if the writers asked a member of the Trigger team to summarize the plot of the previous game and then wrote their own story and then decided that they needed to throw in some random connection with Trigger to make it work. The story is by no means bad, but tying in the elements from this storyline to the one before doesn't seem to work out all that well. Squaresoft is still the master of good storytelling, and what you'd normally expect out of them from the PSone generation will not disappoint.
The gameplay mechanics should be somewhat familiar to you if you've played Final Fantasy. The difference here though is, just like the previous one, there are no random battles, you see all the characters on screen, and the enviorments are interactive. For example, while you sneaking to get on mansion grounds, there will be searchlights everywhere. If you get spotted, it sounds off the alarm and the AI respond accordingly (unlike FF, if a similar situation occurred, most likely you'd have to endure a random battle).
Battles are the best part of the game. It's not going to give you that feel-good emotion you get playing Trigger, but it comes pretty close. Using elements in the game has a very interesting effect on the battlefield, and it's entertaining to try out different combinations and use them against your enemies. Character combo attacks have returned, although they're not as accessible or creative as Chrono Trigger. This may be the fact that Chrono Cross has 40+ characters, most of which if you will never come around to using unless you want to relive the game multiple times, in which most cases...no you probably won't.
Chrono Cross is a great game that should be part of any RPG fans collection. It's does what it needs to do and beyond; just don't expect it to be greater than its predecessor.
EDIT: Unfortunately after putting the game in again I overlooked the biggest factor that seperate the Chrono franchise from the rest of the RPGs: the "New Game+" option. Yes, this feature alone thee gateway to multiple replays. I regrettably retract my previous statement about players not playing through the game more than once. This option not only gives you all the skills and abilities from your previous session with the game, but allows you the advantage of seeing multiple endings by completing certain objectives, breathing more life to an already fantastic game. This also gives you the advantage of going back and seeing anything you might have missed, such as playing with any of the 40+ characters you'll encounter with the game and allow yourself to experiment with them in battle. Sorry folks for the change, but my score has increased by 0.5 to give it the final rating of 9.0.