SZNESXVK Infinite lives
GZELVXSE Infinite life meter (except if you hit a spike)
SXUASXOU Quick pick up
AEUEKKGL Special "squat" high jumps
PPXAOIAA Princess has mega-float
PAXAOIAA Princess has mega-float and lunar descent
PESEGLGA Super moonjumps for Mario
AAEEZGPA Mega moonjumps for Luigi
PENALLGA Super moonjumps for Toad
PAXAPGGA Super moonjumps for Princess
AEXALGZA Speed up enemies
GOEANKAO + USEEEKKA Walk backwards
XVVANSZK + XVNEXSZV Super turbo running
AEVAVIIA + AENEEITA Permanent turbo running
AXSETUAO + ESVAPUEV Super fast run for Mario
AZEEGKAO + EIEEYKEV Super fast run for Luigi
AXNAIUAO + ESNEAUEV Fast run for Toad
AZXALKAO + EIXATKEV Super fast run for Princess
AXNAZSAA + EVNALSEY Super speed enemies

Note: There are two versions given for some of the following Codes.
If one code doesn't work on your game, then try the alternate Code.
YESUAPTE / YESLPPTE Strong Wart
IAVENYZE / IAVEUYZE Strong Birdetta
YEVXVYLE / YEVZNYLE Strong Hawkmouth
AAVENYZA / AAVEUYZA Weak Birdetta
TPEPLAAX / TONENYAX Birdetta spits eggs instead of fireballs (appears in late
levels of the game)
YAXXIYZE Strong Tryclyde
YAVXVGGE Strong Fryguy
YAEXTPGE Strong Clawgrip
PEEPUZAG + IUEPSZAA + TEEPVZPA Start on World 2
ZEEPUZAG + IUEPSZAA + TEEPVZPA Start on World 3
LEEPUZAG + IUEPSZAA + TEEPVZPA Start on World 4
GEEPUZAG + IUEPSZAA + TEEPVZPA Start on World 5
IEEPUZAG + IUEPSZAA + TEEPVZPA Start on World 6
TEEPUZAG + IUEPSZAA + TEEPVZPA Start on World 7