Gameplay - 8
Dissidia is a real solid game, with effective and uncomplicated controls, a camera that does what it's supposed to, and moves that are easy to use and don't require complicated button combos. The arenas are 3-D and destructable, unlike fighting games like Soul Calibur or Tekken where the arena is a small platform.
The goal of the fight is to bring your opponent's HP to zero through use of HP and Brave attacks. The Brave system is new to this game, and bears some explaining. Each fighter starts out with a set number of Brave Points. These function as a defensive barrier and also as a power level. Higher Brave = more powerful attacks and better defense. Using a Brave attack (circle button) steals BP from your opponent and transfers it to your total, increasing it and letting you get the upper hand. However, once you've used an HP attack, your brave points are reset to the original amount. Go below 0 and you enter Break mode, which causes critical hits and extensive HP damage, as well as your opponent gaining all the BP in the pool at the bottom of the screen.
(image courtesy of IGN.com)
The other feature of the fighting is EX Mode, which is like a Limit Break. Your character transforms and has the chance to execute a powerful attack. The attack is dependent on the character you're playing as (ex. Cloud gains his Ultima Weapon and performs Omnislash), and usually features the same kind of trigger/button combo as it did in the original game. Tidus' EX Mode exchanges the sword Brotherhood for his Celestial Weapon (Caladbolg) and lets him perform "Blitz Ace". Similarly to FFX, the Overdrive meter comes up and you have to get it right in the middle for the most damage.
Plot - 8
Behold, a fighting game with a story! While not the best thing SE's ever written, it's still lightyears ahead of the story modes for SC4 and Tekken. Cutscenes abound, and the characters all interact with each other, rather than just showing up to fight. There's even some blurring of good and evil (Jecht and Golbez)! The premise for Dissidia is that two gods, Cosmos and Chaos (you figure out which is good or evil), are fighting and each have enlisted the help of a group of warriors. Cosmos's warriors must battle the villains and find their crystals in order to defeat Chaos and return balance to the world. It's a very Final Fantasy plot, but not as in depth as the console RPG's are.
Characters - 9
The whole cast stays pretty true to their respective game personalities, while being able to interact and even make friendships with other characters (such as Bartz and Zidane, or Terra and Onion Knight). Their voice acting is pretty good, and (go SE!) their mouths match their words! I'm pleased with some of the new voices, like Squall and Zidane, who really sound like I expected them to.
Overall, this game is pretty damn awesome, and I haven't even made it halfway through. There's so much stuff to do besides/in story mode, like Battlegen (an accessory creation system), achievements and a myriad of other options. I've already put something like 20 hours in this game, and I haven't started the second part of story mode yet. It's a must have, and definitely a good reason to get a PSP if you don't have one.