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

• 003-9CF-3BE
  Infinite time (Levels will not end, you will need to switch on effects at game play screen, off after battle mode, on to rebuild the castle and off to go on.)
• 3E0-29B-081 + 090-2AB-7F5 + 000-2BB-F7D Have 6 seconds to rebuild castle walls
• 3E0-29B-081 + 440-2AB-7F5 + 000-2BB-F7D Have 66 seconds to rebuild castle walls
• 3E0-29B-081 + 770-2AB-7F5 + 000-2BB-F7D Have 118 seconds to rebuild castle walls
• 3E0-40B-081 + 1A0-41B-B32 + 000-42B-F71 Levels last 10 seconds
• 3E0-40B-081 + 2A0-41B-B32 + 000-42B-F71 Levels last 25 seconds
• 3E0-40B-081 + 430-41B-B32 + 000-42B-F71 Levels last 50 seconds
• 01E-B3B-F79
  Infinite cannons
• 017-0EB-F79
  Infinite lives