Wario Land
  
Game Boy


Debug mode: 


  Pause the game and press Select 16 times. If done correctly a flashing box should 
  appear around the coin icon. Hold A + B and press Left or Right to edit the 
  numbers for lives, coins, hearts, or time by pushing Up or Down. If you put 
  the flashing box over Wario's head icon and press Up or Start your helmet will 
  upgrade. Press Start to go back to the game.
 
Thanks to Revolution readers Matthew S., Peter van Elburg Boddendijk, Jonathan 
  Dennis, Sebastian Keimel, Nobody, Devil, and Ruud Volkers!