Bubble Symphony

Game select:
Press Up, C, Right, B, A, Left, C, Down at the title screen to select between normal and super game modes.
A sound will confirm correct code entry.

Play as human Rainbow Island characters:
Press Left, Down, Up, B, Right, C, A, Right at the title screen.
A sound will confirm correct code entry.

Bonus options:
Press Left, Right, Left, Right, A, B, C, B at the main menu.
The following extra options will be available: Super game toggle, language select, sound test, sound volume, and audio mode.
A sound will confirm correct code entry.

Always access secret rooms:
Press B, A, B, A, B, A, Left, C at the title screen.
A sound will confirm correct code entry.

No background graphics, new music:
Press A, B, A, B.
A, B, Right, C or Left, A, Left, C, Left, B, Left, C at the title screen.
A sound will confirm correct code entry.

Turbo mode:
Press Down, A, B, C, Left, Right, Left, C at the title screen.
A sound will confirm correct code entry.