We have 3 cheats and tips on GBA. If you have any cheats or tips for Famicom Mini: Super Mario Bros. 2 please send them in here. You can also ask your question on our Famicom Mini: Super Mario Bros. 2 Questions & Answers page.
When you get a 'Game Over' hold A + Start to be able to restart the world in which you died. This will work as long as it is not Worlds 9 A, B, C, or D.
When you beat the main game (Worlds 1-8) eight times and then press B + Start at the 'Title' screen you will be able to access worlds A-D.
When you beat the main game without using any warp pipes you will be able to access World 9.