More Kombat Menu:

 At the story line screen where the words scroll from the bottom to the
 top, press Run, Block, Block, Run, High Punch, Low Punch.  You'll hear
 Shao Kahn say "Outstanding."

 Press  Start, and at the screen with the  different  game modes, press
 and hold Up, and press Start.  Cycle through the various options until
 you reach the dark blue "?" and press A. 

 This is a  More Kombat menu  that enables you to play as Khameleon and
 Human Smoke.

Kombat Cheats:

 At the screen where the words  "For nine generations Mortal Kombat..."
 scroll up the screen,  quickly press left C, top C, right C, bottom C,
 A, B, B, B, A, A.

 You'll hear a confirming sound if you did the trick correctly. Start a
 game and choose Options.

 Highlight the red  "?"  box and a  Kombat  Cheats  menu appears, which
 includes unlimited fatality time and one-round matches.

Secret Endurance Ladders: 

 At the fighter-select screen, put the cursor over Kano, then press and
 hold Down and press Start. You'll hear a thud and screen will shake.  

 Start a one-player game, and at the "Choose Your Destiny" screen, each
 of the towers has several endurance matches.

Play as Motaro:

 At the fighter-select screen, put the cursor on  Sonya, then press and
 hold Up and press Start. The screen will shake. 

 Select  any  fighter, then choose to fight at  either the  Wastelands,
 Jade's Desert, or Motaro's Lair.

 Pick the stage, then  simultaneously  press and hold Left, High  Kick,
 and Low Kick until the match starts. 

 When the fight begins, your fighter explodes into the boss Motaro. 

Play as Shao Kahn:

 At the fighter-select screen, put the cursor on Sonya,  then press and
 hold Up and press Start. The screen will shake.

 Select any fighter, then choose to fight at either  Pit 3, Kahn's Kave,
 or the Rooftop. 

 Pick the stage, then  simultaneously  press and hold Down,  High Punch,
 and Low Punch until the match starts.

 When the fight begins, your fighter explodes into the boss Shao Kahn.