Another World
     At  the  "Push  Start button" screen, press Y, Left, Right, Y. If
you entered the code correctly, a message will appear in the top right
corner  of  the  screen.  Select  puzzle  mode and then arcade mode to
access additional levels.

Bonus characters
     At  the  "Push  Start button" screen, press Y, Right, Left, Y. If
you  entered the code correctly, a message will appear in the top left
corner of the screen.