The Coming of the Quantum Cats can - given different social conditions - develop completely different character traits (timid or assertive, benevolent or predatory, etc.) The title refers to the famous thought-experiment known as "Schrödinger's Cat", where the outcome of a real-world event depends on a quantum event. By some interpretations, the real-world object, in this case a cat, must be in two states simultaneously until it is observed. However, the story is more closely related to the many-worlds interpretation of quantum mechanics where all possible outcomes of an event occur, each in its own parallel universe. The same concept was treated, somewhat more pessimistically, in
Dead or Alive Ultimate Sega Saturn version, and is generally considered more of a collector's disc than for its content. "Dead or Alive Ultimate 2", being a remake created after the debut of "Dead or Alive 3", takes elements and mechanics from both its original iteration and successor. The action of 3D-axis movement is as free-formatted as "DOA3", and Hitomi is now a playable character albeit outside story mode. Other elements have been kept intact from "DOA2". These include higher damaging counters than in "DOA3", environmental hazards not warranting a knockout on a character, and a counter mechanism that is much harder to execute.