> Highlight a character and press Start (up to three times) to toggle the alternate costumes of each character.
(courtesy: GameFan)

> At the Title screen, press Up, Up, Down, Down, Left, Left, Right, Right.  You should hear the announcer say "Outstanding!" to confirm the code.  Now, go to the Main Options menu, then press L+R shift to activate the Cheat Menu.
(courtesy: GameFan)

> Enter one of the following codes at the Versus Mode screen to activate a cheat.  There are two three-digit icon boxes at the bottom of the screen.  The first icon in each box is controlled with Low Punch, the second with Block, and the third with Low Kick.
 
One-hit win - 123 123 
Noob Saibot mode - 012 012 
Red Rain (On the Rain stage) - 020 020 
Explosive Kombat - 050 050 
Drawn weapons can not be lost - 002 002 
Disable throws - 100 100 
Disable max damage - 010 010 
Disable throws and max damage - 110 110 
Random weapon appears - 111 111 
Start with random weapon - 222 222 
Start with weapons drawn - 444 444 
Many weapons - 555 555 
Silent Kombat - 666 666 
Big heads - 321 321 
Fight in Goro's Lair (Spike Pit) - 011 011 
Fight in The Well (Scorpion's Stage) - 022 022 
Fight in Elder God's (Blue Face) stage- 033 033 
Fight in Tomb Stage - 044 044 
Fight in Rain Stage - 055 055 
Fight in Snake Stage - 066 066 
Fight in Shaolin Temple - 101 101 
Fight in Living Forest - 202 202 
Fight in Prison (Fan Stage) - 303 303 
Fight in Ice Pit - 313 313
(courtesy: GameFan)

> Go to the Character Selection screen, highlight the "hidden" option, press and hold L+R shift buttons, and enter the following codes:

Goro – Up, Left, A
Noob Saibot – Up, Up, Left, Left, Left, Left, A
Sektor – Up, Up, Up, Up, Left, Left, Left, Left, A
(courtesy: GameFan)

> In Arcade mode pick your fighter, then choose your destiny, but dont press "A" yet.   Press Start, and then the tower will rotate and your opponents order will change.
(courtesy: GameFan)