 Generated controversy upon its release for its pioneering use of  "jiggle physics", whereby female characters (sizeable) breasts are  modeled to react dynamically to any forces applied to them. In other  words, the characters breasts bounce around whenever they move  about. Although the "Dead or Alive" series has since become  synonymous with jiggle physics, by 2004 numerous other titles had  incorporated the system, including  _Mortal Kombat: Deadly Alliance (2002) (VG)_ (qv), "Outlaw  Voleyball" (2003) and even _Sims 2, The (2004) (VG)_ (qv)