A Bug's Life
Passwords

Level 2: 9LLK
Level 3: BL26
Level 4: 5P9K
Level 5: 6652
Level 6: BKK2
Level 7: 2PLB
Level 8: 6562
Level 9: L59B
Bonus: BL26

Adventure Island II
Stage Select

Enter the code: 0 8 9 4 on the Password Screen. Now you can start on the first stage with 99 of every power-up.

Avenging Spirit
Expert Level

At the Title Screen, simultaneously press UP, A, and B. When you hear a tone, press START to begin.