Enter the following passwords at the password screen.

Password	What to unlock
04-6J-85-2C	Level 99 No Areas Cleared.
2H-02-72-H8	Megakat City and Megakat Bank completed.
6B-88-40-H4	Megakat City completed.
B4-89-B2-1H	Megakat City, Bank, Madkat, and Sea Boat completed.
C9-7F-72-13	Megakat City, Bank, and Madkat Amusement Park completed.
J5-B7-FB-84	Bonus Level.