Hint:
 When you're at the any level, when you haven't any life, before the screen 
 with the inscription "Game Over" and the face who is crying appear, click 
 on the "Game" menu then "Password" and type castillo. And He, Hey now you're 
 on level one, but you have unlimited lifes and again you can type one of the 
 following passwords and you can go to other level with unlimited lifes too!
 Easy, huh...
 
 Code - Result
 Level 1   -  No code enought.
 Level 2   -  ?
 Level 3   -  Playa
 Level 4   -  Oceano
 Level 5   -  Puerta
 Level 6   -  Castillo