The following are known Game Genie Codes for Fish Dude on Nintendo Game Boy.

• 215-25F-081
  No timer
• 002-3DF-E62
  Start with 1 life
• 042-3DF-E62
  Start with 5 lives
• 082-3DF-E62
  Start with 9 lives
• 0E2-3DF-E62
  Start with 15 lives (Ignore the counter for the 5 lives)
• 002-A8F-3BE
  Infinite lives