Mortal Kombat II.
 No.  Code  Effect
   1  CVYA-BA7N  Timer is 2x as fast
   2  LBYA-BA7N  Timer is 2x as slow
   3  ABVT-BE64  Infinite time
   4  RETT-A6Y6  Activate testing mode in options screen

Codes 5 Thru 21 are for 1-Player ONLY - Can't see ending.
   5  ACMT-BE76  Always fight Kung Lao
   6  AGMT-BE76  Always fight Liu Kang
   7  ALMT-BE76  Always fight Cage
   8  ARMT-BE76  Always fight Baraka
   9  AWMT-BE76  Always fight Kitana
 10  A0MT-BE76  Always fight Mileena
 11  A4MT-BE76  Always fight Shang Tsung
 12  A8MT-BE76  Always fight Rayden
 13  BCMT-BE76  Always fight Sub-Zero
 14  BGMT-BE76  Always fight Reptile
 15  BLMT-BE76  Always fight Scorpion
 16  BRMT-BE76  Always fight Jax
 17  BWMT-BE76  Always fight Kintaro
 18  B0MT-BE76  Always fight Shao Kahn
 19  B4MT-BE76  Always fight Smoke
 20  B8MT-BE76  Always fight Noob Saibot
 21  CCMT-BE76  Always fight Jade
 22  RFWA-A6Y8  Fatalities can be done at end of any round
 -- computer wins after winning 1 round
 23  AP9A-BA7R  Lazy opponent!
 In 2nd round, loser of 1st round lies on ground
 (causes computer to act weird in some rounds)
 24  A3XA-AJA4  Player has 4x times as long to do fatalities, etc.
 25  AB1T-CA4G + AA9T-CA3J    Auto fatalities
 26  AB1T-CA4G + BT9T-CA3T  Auto friendship
 27  AB1T-CA4G + RE9T-C6V0  Auto babalities
Codes 28 Thru 36 Work at most distances.
 28  A13A-AA5R  Mileena's Sai Throw does massive damage
 29  A56A-AA46  Liu Kang's High Fireball does massive damage
 30  A56T-AA2C  Kung Lao's Hat Throw does massive damage
 31  A95A-AA5C  Cage's Shadow Kick does massive damage
 32  AX0A-AA86  Reptile's Force Ball does massive damage
 33  AX2A-AA8R  Shang Tsung's Flaming Skull attack does massive damage
 34  AX3A-AA46  Kitana's Fan Throw does massive damage
 35  A54A-AA8G  Baraka's Blade Spark does massive damage
 36  AX1T-AA3J  Rayden's Lightning Bolt does massive damage