Extra lives:
Press Down + Select + B at the title screen.

Expert mode:
Press Up + Select + B at the title screen.

In-game reset:
Press Select + Start + A + B during game play.

Random percentage:
Find a female blob after rescuing an animal helper. This may be easily done on level 5-3.

Bonus options:
Collect all of the Rainbow Drops. Return to the Boss rooms and achieve a perfect score in all bonus rounds. Find a female blob in any stage, then complete the game to achieve a 100% score. Press A and select "Option" to fight the Bosses, access the bonus rounds, and start a sound test.

Hint: Facing the Dark Matter Boss:
Get all the Rainbow Drops before fighting King Dedede.

Hint: Finding secret rooms:
Use Spark in dark rooms with Spine and the Spark power. Try to enter the doors or pictures that may appear.

Hint: Freeing the Rainbow Drops:
Use the following powers on the blocks in the Rainbow Drop rooms.

1: Grassland: Parasol
2: Forest: Spike
3: Ripple Field: Rock
4: Iceland: Fire
5: Red Canyon: Spark
6: Cloudy Park: Cutter
7: Castle: Ice
End: Fire, followed by Stone, Spike, Ice, and Cutter