The first Dead or Alive was sort of the Tomb Raider answer to fighting games. It didn't offer anything new or outstanding, but did feature tons of tightly clothed women with DD busts that, um, jiggled (really, I was searching for a better word, but this is the most accurate). And that is the full success of Dead or Alive, period.
Now comes Dead or Alive 2 for the Dreamcast. Outside of the graphical improvements, Tecmo has gone ahead and made many of the levels interactive. In older fighting games you could knock over a stack of oil cans, or cut up a box, but in Dead or Alive 2 you are able to knock people completely off of buildings into a completely different backdrop. Some of the levels even do it for you, in the snow level if you jump to actively the ground will give, and down you go to the underground caves. Awesome.
The game play has been improved, thankfully. The basic control is intact, but the ease of special moves and even counters has greatly improved. The first game seemed like it was ripping off Virtua Fighter, now it feels like Virtua Fighter SHOULD be ripping off of Dead or Alive. You might not think so with the extremely simple button set up, but the control really is extremely deep and challenging.
The game features a wonderful two player mode, as well as a simple arena four player mode. I completely understand the limit of arena size in the four player modes, but it would have been nice for a slightly larger selection. The characters are extremely large and wonderfully animated, as well, but I can't help but yearn for the multitude of costumes and new characters that the PlayStation 2 version housed.
In the end Dead or Alive 2 comes close to topping Soul Calibur, but doesn't quite hit it's mark (at least not like it did on the PlayStation 2). This has the workings for a classic fighting game, as well as some of the most innovative features in current fighting games, but it has a little more work to go before it's perfected. Close, but not quite in the same ballpark as Soul Calibur.