The following are known Game Genie Codes for Harley’s Humongous Adventure on Super Nintendo Entertainment System (SNES).

• Start With 2 Lives
  DFCF-A7F1
• Start With 6 Lives
  D9CF-A7F1
• Start With 11 Lives
  FDCF-A7F1
• Start With 26 Lives
  49CF-A7F1
• Start With 51 Lives
  9DCF-A7F1
• Start With 100 Lives
  BBCF-A7F1
• Infinite Lives
  C2C8-07B5
• Start With 4 Hearts
  D6CF-ADB1
• Start With 5 Hearts
  DCCF-ADB1
• Protection Against Some Hazards
  C2C0-0DB5
• Start With 10 Of Every Weapon
  FD22-6415
• Start With 25 Of Every Weapon
  4922-6415
• Start With 50 Of Every Weapon
  9D22-6415
• Start With 99 Of Every Weapon
  BB22-6415
• Get Only 5 Ammo From A Weapon Power-Up
  D98D-DDB9
• Get 20 Ammo From A Weapon Power-Up
  4D8D-DDB9
• Get 30 Ammo From A Weapon Power-Up
  7D8D-DDB9
• Get 40 Ammo From A Weapon Power-Up
  0D8D-DDB9
• Get 50 Ammo From A Weapon Power-Up
  9D8D-DDB9
• Infinite Ammo
  DD87-A4B0
• 20 seconds To Collect Power-Ups On Level 1
  F08C-A704
• 60 Seconds To Collect Power-Ups On Level 1
  7A8C-A704
• 90 Seconds To Collect Power-Ups On Level 1
  9C8C-A704
• 60 seconds To Complete The Vent Level
  7A88-A7D4
• Infinite Time On Vent Level
  3C83-ADA4
• Start With Maximum Fuel On Every Level
  6DCF-04B1
• Any Fuel Power-Up Gives Maximum Amount
  DDC4-6495
• Infinite Jet Fuel (Must Already Have Some To Fly)
  DDCD-6DF5
• Hit X On The Title Screen With The House To Get Level Select Menu
  D43E-046F