Awesome game, great to play with a friend. =)
The storyline is also very cool. Starting from the intro movie, we see the characters stumbling upon a piece of Soul Edge, and there's not a second of doubt in their mind. But they are NOT all after the same objective. While some wants to destroy it, others seek it, giving a great twist to the story. The Arcade battle has one scene with someone destinied to battle, but it is no good effort in trying to have the story implied in the Arcade mode.
The true wonder of the game, is Weapon Master mode, where you travel the world, battle opponents, gaining glory and reputation in your quest to destroy Soul Edge. With a variety of enemies and different objectives, this really stands out as the true wonder. Earning money and buying weapon is also loads of fun, and battleing versus your friends is ton of fun.
That said, I guess there's not much more to say. Enjoy. =)