The same, but more and better.
To read some reviews of Soul Calibur III, you'd think Namco had rushed out a half-baked, pointless remake of SCII with better graphics. To say that nothing could be further from the truth qualifies for understatement of the decade. Leaving aside the new story mode for a moment, let's look at the two biggest added features- the ability to create custom characters, and the Chronicles of the Sword mode. At first, both might look a little limited- there aren't all that many custom parts, you pick a 'Job' for each character which determines which move set you use, and yes, you can win the first few CotS battles just by knowing how to fight. Oh, and you can only create 3 custom characters. But dig a little deeper, and things get a lot more interesting.
For a start, that Gladiator you just created as the lead character of the CotS story may use a sword and shield- but it's a new style, not Sophitia, Cassandra or Lizardman. Or if the new hero is a Dancer, she fights with a couple of tambourines. A Barbarian with an Iron Sword might look like Siegfried at first glance, but he'll have another new moveset. Then there's Lance, Katana, Katana + Shuriken, Knife + Bomb, Kunai (two knives), Wave Swords and the Tae-Kwon-Do based Kick Edge. Eventually, if you play them enough, each Job will pick up several weapon styles including two 'soul of' styles, which let you copy the existing character's moves. So if you want to make an armoured knight who fights like Voldo, you can..
At the same time you're playing about with all this, you'll meet a hatload of minor characters, many of whom are unlockable as playable characters. Many of these have been created using the custom character system, and as they are unlocked, so are the parts used to make them. In all, there are over 300 custom parts for each gender. As for the number of characters, eventually you can buy it up to 10, not counting your CotS heroes.
As for the CotS mode itself, it's not long before it starts to show a bit of depth. Later missions will quite happily throw sneak attacks at your stronghold when you're out of position, or throw you up against seemingly impossible odds- and all the while, even if you lose, you'll just keep on unlocking new stuff to play with.
The story mode, with new interactive cutscenes (Think Shenmue, but usually with only one button press), decisions on your route and secret bonus battles is another major improvement. You might eventually start to see some similarities in the characters' stories, and there are less events than perhaps their should be, but it still adds a lot of flavour to the progression of opponents, as well as giving you a reason to replay. Even the endings tend to have an interactive component, and the Event Theatre lets you replay them to have another try at getting them right- or to let you see the price of failiure. (As an aside, did I mention the return of Rock, with guest appearances from Hwang, Li Long and Charade?)
It's true to say that Soul Calibur III can be frustrating at times. The CotS mode does like to throw very high-level opponents at you, especially early on, and the 'World Tournament' mode, which tasks you with winning 12 consecutive tournaments (!) is more irritating than fun, especially with the mystifying decision not to let you use your custom characters in it. The created characters also suffer from a relatively small pool of voices who repeat stock phrases a tad too often. But there's just so much in there, waiting to be discovered, that the occasional bum note is to be expected. Overall, unless you're REALLY going to miss Spawn, Heihachi or Link, this is the finest installment in the Soul Calibur saga to date.
Soul Calibur IV, anyone?