If you want to more efficiently practice collections of later stages, the following passwords will warp you there:

Area 6 - SMPSN Area 11 - CVFTZ Area 16 - BPQGY Area 21 - TRQCZ Area 26 - CQQSH Area 31 - STFVF Area 36 - DJZZZ Area 41 - BLBJN Area 46 - DFLTQ

LEVEL SELECT

To warp to any specific level in the game, enter "LVDYK" as the password, and then on the title screen, hover over "1UP GAME", hold L, R, and Left, and press Start. Then use A, X, L, or R to choose any stage.