Mortal Kombat II Secrets and Unlockables (PSX)

Mortal Kombat II (also referred to as MKII or Mortal Kombat 2) is an arcade game and the second title in the Mortal Kombat fighting game series. Storywise, the events before and during this game are portrayed in Mortal Kombat: Shaolin Monks. Essentially, Mortal Kombat II is an extension of the game system of Mortal Kombat. A few normal moves have been added (crouching punch, for example). The roundhouse kick was made more powerful in part II, and like the uppercut, launched opponents into the air. Additionally returning characters gained new special moves. The game also introduced multiple fatalities, as well as additional finishing moves to the franchise.

However, each character still shared generic attributes – speed, power, jump height and airtime – and all normal moves were similar between each character. As with its predecessor, the only thing differentiating each character were their appearance, special moves, hit detection, and finishing moves. This has also led to the similar criticism of the fighting system being very shallow and lacking any real character depth. However, the game plays slightly faster and much more smoothly than the original.

As with its predecessor, matches in the game are divided into rounds. The first player to win two rounds, by fully depleting his/her opponent's life bar is the winner. At this point the loser's character will become dazed and the winner is given the option of using a finishing move. In addition to the fatalities of its predecessor, the winner could also use babalities, friendships, and stage specific fatalities. (Wikipedia)

Unlockables

Noob Saibot
Noob Saibot - Complete 2 players challanges 25 times in a row to unlock Noob Saibot

Secrets

Fight Jade
This only works in 1 Player mode. During the fight that is right under the '?' box, defeat your opponent by only using Low Kick. After the fight, you will be transported to Goro's Lair to fight Jade.

Fight Smoke
This works in both 1 and 2 Player modes. During a match on The Portal stage, if you get the 'Toasty!' guy to appear, quickly press Down + Start. If done correctly, you will be transported to Goro's Lair to fight Smoke.

Here's the game's revamped version for the PS3: