Mortal Kombat Gold

Cheat Mode: 
At the Title screen, press Up, Up, Down, Down, Left, Left, Right, Right. You'll hear the word "Outstanding" to confirm. Now hold L + R at the Options selection to bring up the cheat menu. 

Play as Goro: 
First enable the cheat menu. Now at the character selection screen, highlight "Hidden," hold L + R and choose Shinook.

Play as Sektor: 
First enable the cheat menu. Now at the character selection screen, highlight "Hidden," hold L + R and choose Cyrax.

Play as Noob Saibot: 
First enable the cheat menu. Now at the character selection screen, highlight "Hidden," hold L + R and choose Reiko.

Kombat Codes 
111-111: Free Weapon
123-123: No Power
222-222: Random Weapon
012-012: Noob Saibot Mode
321-321: Big Heads
020-020: Red Rain
444-444: Armed & Dangerous
050-050: Explosive Kombat
555-555: Many Weapons
002-002: All Time Weapons
666-666: Silent Kombat
100-100: Disable Throws
010-010: Disable Max Damage
001-001: Unlimited Run
110-110: No Throws & Max Damage
011-011: Goro's Lair
022-022: The Well
033-033: The Elder Gods
044-044: The Tomb
055-055: Wind World
066-066: Reptile's Lair
101-101: Shaolin Temple
202-202: Living Forest 
303-303: The Prison
313-313: Ice Pit