Ball select:
Enter GFXJF as a password to change the ball into various objects, including a rag doll, space man, and alien.

Sound test:
Enter NRRRP as a password.

Change gravity:
Enter ZLJPJ as a password to change the gravity to match any planet in the solar system.

Display best time screen:
Enter ZNGGX as a password.

Level select:
Enter QWNQP as a password. The title screen will appear again with the level number displayed. Press Up or Down to select any level from 1 to 99, then press Start.

Second and third level planes:
Enter MHWYR as a password to access the second plane, or HCCWD to access the third plane of levels.

Final level:
Enter WRJMH as a password.