Bonus levels:
Press A, Up, B, Down at the title screen.

Expert mode:
Press A + B at the title screen to increase the difficulty level.

Time trial passwords:

Level	Password
20	DINO
30	SHAM
40	PARCK
50	CHUN CHUN
60	MAITA
70	CHOKKINTA
80	BUBLEN
88	MADAM YAN