The following are known Game Genie Codes for Nightshade on Nintendo Entertainment System (NES).

• Invincible At Fights
  TKISGT
• Walk Through Walls And Wall Everywhere On The Screen
  EXTASK
• Invincible But Not At Fights
  TKISAI

Nightshade Turns Into a… Codes

• Ninja
  TEAGIP
• Gent
  GEAGIP
• Mummy
  YEAGIP
• Green Gent
  LEAGIP
• Pink Gent
  ZEAGIP
• King Rat
  GEAGIO
• Rat
  ZEAGIO
• Statue
  AEAGIO
• Goliath
  YEAGIO