GameBoy Advance Cheats: Yoshi's Island : Super Mario Advance 3 Cheats

Easy lives
When you see a Bandit, use eggs or a portable green watermelon on him to first get three coins, then three lives.

Touch Fuzzy Get Dizzy: Unlimited lives
Grab a Melon Bug (the creature that rolls up into a ball) and go to the pipe with Shy Guys jumping out of it. Spit the Melon Bug close to the pipe on the left-hand side. When Shy Guys jump out, after a while you will get a "1-Up" for each time a Shy Guy hits the Melon Bug when it is in its melon form.