Mortal Kombat 4

Hidden Options:
On the Title Screen, choose Options.
Highlight Continues and hold Run and Block (C-Left and C-Down are the default buttons for Run and Block)
until a special options menu appears.
To exit the menu, highlight Exit and press the A Button.

Hidden Characters:
There are several hidden kombantants in Mortal Kombat 4.
To access them, select HIDDEN on the character select screen, then do as follows:

-NOOB SAIBOT After entering Hidden on the character select screen, press Up, Up and Left (the cursor will be on Reiko) and then press Run and Block together.

-GORO To Play as Goro, select Hidden on the character select screen, then press Up, Up, Up and Left (the cursor will be on Shinok). Press Run and Block together to play as Shinok.

-MEAT To play as Meat, you'll have to go to "Group Mode" and play as every character, and win every match. After you finish playing, pick any character, but when the match starts you will be playing as Meat. Meat has all the moves of the character that you chose.