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

• Start With 2 Lives
  012 19F E66
• Start With 6 Lives
  052 19F E66
• Start With 10 Lives
  092 19F E66
• Start With 1 Energy Bar For First Knockdown Only
  012 21F F76
• Start With Two Energy Bars For First Knockdown Only
  022 21F F76
• Start With Lots Of Energy
  00F 03F 3BF
• Pick Up Gun & Keep Until End Of Level
  00C B6F 3BE
• Gun Has 1 Bullet
  013 D9C DD6
• Gun Has 5 Bullets
  053 D9C DD6
• Gun Has 9 Bullets
  093 D9C DD6
• 2 Lives After 1st Continue
  017 EAD E66
• 6 Lives After 1st Continue
  057 EAD E66
• 10 Lives After 1st Continue
  097 EAD E66
• Infinite Continues
  007 E5D 3B7
• Start With 1 Energy Bar (After 1st Life)
  014 37F F76
• Start With 1.5 Energy Bars (After 1st Life)
  024 37F F76
• Start With 2 Energy Bars (After 1st Life)
  034 37F F76
• Enemies Warp All Over The Place (Very Hard To Kill)
  AFD 0AE F70