See the Famicom disc system intro
When you turn on your Game Boy Advance hold AB at the same time to see an intro from the Famicom Mini version which is Mario and Luigi fighting over a lightbulb and if you press B again you will get to the loading screen from the Famicom Disc system all of which were just added as an easter egg for the GBA version that you can not normally see on this game
Warp To World 3
To warp to world 3 you must be in World 12 When you reach an area where there is a pipe a few bricks and a SteelShelled Koopa hit the first brick on the left A beanstalk will pop out Climb up the beanstalk and at the top run forwards until you reach the warp pipe that takes you to World 3
