The following are known Game Genie Codes for Fist of the North Star on Nintendo Game Boy.

• 21E-9FF-4C1
  Almost invincible
• 21F-A5F-4C1
  No energy loss from weapons that are thrown
• 05B-CCE-E6E
  Start on level 5
• 09B-CCE-E6E
  Start on level 9
• 40F-F7E-195
  Start with 25% energy
• 7F4-F7E-195
  Start with 50% energy
• C44-F7E-195
  Start with 75% energy