call me thief luigi.lol.you have to beat the last boss in w2 to unlock w4 then you have to
beat the last boss in w5 to get w7.i know.it took for ever for me to figure THAT out.

i forgot to mention you have to be tiny!

beat the final boss of world 2 as mini mario/luigi 2 unlock world 4.

beat the final boss of world 5 as mini mario/luigi 2 unlock world 7.

i cant beat the boss with tiny eaither i cant beat the one on world two cause with tiny
when u bounce on the worm to kill it , tiny mario just bouncess of him and u cant even
make the worm loose a life UGGGHH im so frustrated

You have to do a butt-slam on the boss. Like how you jump on a box from above. Jump the
press down and you'll do some damage.