Enter these codes at the password screen:

Level 1 (Groëland)
New game

Level 2 (England)
H7Z3

Level 3 (Monaco)
FDRO

Level 4 (Brasil)
ZWWP

Level 5 (USA)
SR8Q

Level 6 (Holland)
GZW7

Level 7 (Japan)
Z6F1

Level 8 (Kenya)
KDC3