Mortal Kombat: Unchained is the title of the PlayStation Portable version of Mortal Kombat: Deception, developed by Just Games Interactive. The game was shipped on November 13, 2006 in North America, November 24, 2006 in Europe, and December 9, 2006 in Australia. The game includes all the characters from the GameCube version, and four more characters—Blaze, Frost, Jax and Kitana—from Mortal Kombat: Deadly Alliance that are exclusive to the PlayStation Portable system. The four characters, however, have one fatality and no hara-kiri in contrast to other characters. An Endurance mode is an exclusive new feature where players can compete against a constant wave of opponents. The system's Wireless Ad-hoc functionality can be used for multiplayer games. Characters who remain hidden in the other version appear unlocked in Unchained. The producer Shaun Himmerick commented that the staff wanted to show players characters that were difficult to obtain in Deception such as Liu Kang. Although Midway did not develop the game, they helped Just Games Interactives optimize their code and the Wi-Fi linking, as they wanted to keep the framerate very high.
Source: Wikipedia, "Mortal Kombat: Deception", available under the CC-BY-SA License.