Access Bonus Levels even if you die (Classic Mode)
Enter the code at the "Classic" mode's title screen:
L, R, L, R, L, R, Right, Select.
Level 20 will have a door appear. Touch it, to enter the bonus round.
Power Up! Mode (Classic Version)
At the "Classic" Mode title screen enter:
Select, R, L, Left, Right, R, Select, Right.
This is the same effect as collecting shoes
(Move faster, make bubbles faster)
Secret Coke can item (Classic Mode)
Type in I.F at the high score table. A chime will confirm the
cheat has worked. Doing this will sometimes make a coke can appear on
your next game on floor 1. collect it and it will start a meteor
shower that will kill on screen enemies.
Super Bubble Bobble (Classic Version)
Firstly, beat boss in classic mode with 2 players. Enter code at
"Classic" mode title screen: Left, R, Left, Select, Left, L, Left,
Select. This unlocks the harder mode of the game.