The following are known Game Genie Codes for Shinobi on SEGA Game Gear.

• Infinite Energy
  21F 055 2A2
• Infinite Lives
  006 06D 3BE
• Start With 6 Lives
  06B 75C F72
• Start With 8 Lives
  08B 75C F72
• Start With 9 Lives
  09B 75C F72
• On Highway Stage, Jump Onto Road And Stop Traffic
  21E BA5 2A2