KID ICARUS

Hidden continues:
Quickly before the title screen appears press B, A, B. Those
exclusive continues will now be accessible.

Infinite lives:
This passcode will not only grace you with infinite lives but 
also dish out 640 hearts. Enter 8UUUUU UUUUUU UUUUUU UUUUUU 

Passwords:
wanna start at the last level with 640 hearts and unlimited life?
then try one of these "DANGER !!!!!!" or "TERROR HORROR".

Invincible:
use  this code "ICARUS FIGHTS MEDUSA ANGELS" and you'll be invincible
in the rest of the game, you start at the overworld fortress.