Crack Down.

 No.  Code  Effect
   1  9W6T-BCKL + AW6T-AABN  Start at stage 2
   2  9W6T-BCKL + BC6T-AABN  Start at stage 3
   3  9W6T-BCKL + BW6T-AABN  Start at stage 4
   4  AC6T-AACG + WW6T-BCCJ  Player 1 starts with 1 life
   5  AC6T-AACG + YC6T-BCCJ  Player 1 starts with 2 lives
   6  AC6T-AACG + V46T-BECJ  Player 1 starts with 6 lives
   7  AC6T-AACG + R46T-BECJ  Player 1 starts with 11 lives
   8  AC6T-AACG + Z46T-AG4J  Player 1 starts with 26 lives
   9  AC6T-AAD4 + WW6T-BCD6  Player 2 starts with 1 life
 10  AC6T-AAD4 + YC6T-BCD6  Player 2 starts with 2 lives
 11  AC6T-AAD4 + V46T-BED6  Player 2 starts with 6 lives
 12  AC6T-AAD4 + R46T-BED6  Player 2 starts with 11 lives
 13  AC6T-AAD4 + Z46T-AG56  Player 2 starts with 26 lives
 14  AC6T-AAC6 + FC6T-AG48  Player 1 starts with 50 machine gun rounds
 15  AC6T-AAC6 + GW6T-BLL8  Player 1 starts with 100 machine gun rounds
 16  AC6T-AADG + FC6T-AG5J  Player 1 starts with 50 cannon rounds
 17  AC6T-AADG + GW6T-BLMJ  Player 1 starts with 100 cannon rounds
 18  AC6T-AADT + 6C6T-BRDW  Player 1 starts with 6 super bombs
 19  AC6T-AADT + 8C6T-BRDW  Player 1 starts with 9 super bombs
 20  AVMT-AA5W + AVNA-AA4R  Player 1 has infinite super bombs
 21  AC6T-AAET + FC6T-AG6W  Player 2 starts with 50 machine gun rounds
 22  AC6T-AAET + GW6T-BLNW  Player 2 starts with 100 machine gun rounds
 23  AC6T-AAE4 + FC6T-AG66  Player 2 starts with 50 cannon rounds
 24  AC6T-AAE4 + GW6T-BLN6  Player 2 starts with 100 cannon rounds
 25  AC6T-AAFE + 6C6T-BRFG  Player 2 starts with 6 super bombs
 26  AC6T-AAFE + 8C6T-BRFG  Player 2 starts with 9 super bombs
 27  AVMT-AA76 + AVNA-AA2G  Player 2 has infinite supply of super bombs
 28  ADMT-AADL + WXMT-BCDN  Player 1 continues with 1 life
 29  ADMT-AADL + YDMT-BCDN  Player 1 continues with 2 lives
 30  ADMT-AADL + V5MT-BEDN  Player 1 continues with 6 lives
 31  ADMT-AADL + R5MT-BEDN  Player 1 continues with 11 lives
 32  ADMT-AADL + Z5MT-AG5N  Player 1 continues with 26 lives
 33  ADNA-AAFT + WXNA-BCFW  Player 2 continues with 1 life
 34  ADNA-AAFT + YDNA-BCFW  Player 2 continues with 2 lives
 35  ADNA-AAFT + V5NA-BEFW  Player 2 continues with 6 lives
 36  ADNA-AAFT + R5NA-BEFW  Player 2 continues with 11 lives
 37  ADNA-AAFT + Z5NA-AG7W  Player 2 continues with 26 lives
 38  ADST-AAGY  Continue with 0 machine gun rounds
 39  BMST-AAGY  Continue with 10 machine gun rounds
 40  GMST-AAGY  Continue with 50 machine gun rounds
 41  NXST-AAGY  Continue with 100 machine gun rounds
 42  ADST-AAG0  Continue with 0 cannon rounds
 43  BMST-AAG0  Continue with 10 cannon rounds
 44  GMST-AAG0  Continue with 50 cannon rounds
 45  NXST-AAG0  Continue with 100 cannon rounds
 46  ADST-AAG2  Continue with 0 super bombs instead of 4
 47  AMST-AAG2  Continue with 2 super bombs
 48  A1ST-AAG2  Continue with 5 super bombs
 49  BHST-AAG2  Continue with 9 super bombs
 50  BDMA-AA9E  Infinite lives--player 1
 51  BDNA-AA3N  Infinite lives--player 2
 52  1K3T-FBFC + 6B3T-EOPE + JV3T-EL7G    Get first 1-up at 1,000 points
 53  HV3T-FEP8 + AF3T-EAGA  Get 1-ups every 10,000 points
 54  RF3T-E60R  1-up worth nothing
 55  LK3T-FJ0R  1-up worth double
 56  LK3T-FN0R  1-up worth triple