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

• Enemy’s Fatigue Level Doesn’t Go Down
  GZOLIXVK
• Your Fatigue Level Doesn’t Go Down
  GZOUIXVK
• Your Fatigue Level Goes Down Faster
  YLEUIXYN
• Your Fatigue Level Goes Down Slower
  NYEUIXYN
• Don’t Lose Energy From Fighting
  SZSLTXVK
• Your Fatigue Level Never Rises
  SZNLPXVV
• More Damage From Fireballs
  ZAKSIYPA