During their fight, Hayabusa defeats him and restores some semblance of his memory. Eventually, Hayabusa comes face to face with the evil Tengu. He defeats Tengu, winning the tournament. The graphics and gameplay were enhanced and based on a better game engine than the one used in the first game, which allowed the characters and stages to appear less angular and more detailed. A popular and commonly discussed feature, one credited to Tomonobu Itagaki, was the level of graphical detail Tecmo put into the animated breasts of the female characters, as Tecmo went so far as to create a physics engine dedicated entirely to the animation of the female characters' breasts. "Dead or Alive 2" used the song "Exciter" by Bomb Factory in its opening sequence. Also used as a background track was "Deadly Silence Beach" and "Clumsy Bird". Both tracks can be found on the self-titled mini-album "Bomb Factory" and on the "Dead or Alive 2 Soundtrack". Two soundtrack CDs were released in 2000 by Wake Up in Japan: "Dead or Alive 2 Original Sound Trax" (KWCD-1001) and "Dead or Alive 2 Original Sound Trax" (KWCD-1004). Several Japanese guide books for the game were published by SoftBank ("Dead or Alive 2 Perfect Guide", "Dead or Alive 2 Perfect Guide Dreamcast Ban", "Dead or Alive 2 Hard Core Perfect Guide") and Dengeki ("Dead or Alive 2 Kōshiki Kōryaku Guide", "Dead or Alive 2 Kōshiki Kōryaku & Girls", "Dead or Alive 2 Hard Core Kōshiki Kōryaku Guide"). Nine different versions (excluding DOA2 Ultimate on Xbox and the two PSN releases) of "Dead or Alive 2" were released: two for the arcade market, and the others were home versions. Tomonobu Itagaki and Team Ninja were constantly enhancing the game for both the Dreamcast and PlayStation 2 as they worked towards their vision of the "ultimate fighting game". The Dreamcast port was first released in North America on February 29, 2000. It was identical to the arcade Millennium update release, but added the usual Versus and Sparring modes, as well as Team Battle Mode. This version also featured a simplified hold system, which would become standard for the rest of the series. Unlike home ports of the first "Dead or Alive" game, there were no unlockables in this release. "Dead or Alive 2" was the only game that Tecmo published on the Dreamcast.