Level Select
Enter DDFFI as a password and select the 1-Player Continue Round option. Press A or B to select a new starting level from 1 to 112.

Super Bubble Bobble Graphics
Enter HCICD as a password.

Best Ending
Surround the enemy in the final level with bubbles and then press Start, Select, Start to bring a second player into the game. Then, pop the bubbles to see the “Happy Ending”.

This will also enable the sound test option.