Go to the first level of Hotcha Springs and Get to a room with a rock in the middle and 2 lines of octupie.. Then keep using ultra star spin back and forth on each side and they keep respawning and when you're done hit the rock into both the top left and bottom right and get the pearls there. And to the person asking if it's hard to beat Mashtooth's 2nd form.. Just hold it on a toble and beat the crap outa the y button and you'll get it eventually.
Using either Stafy or Stapy complete Boss mode (Big Bossdown) with a time less than 9:00 to unlock World 10 which is a series of 6 time attack levels which have their own Boss. To Battle the new Boss complete the levels in less than the indicated time.
If you find a treasure chest with a Mini G challenge, then you can play a minigame and keep it even if you lose it. You can find these challenges on the first level of Sogwood Forest, Skydye Heights, and the S.S. Logwater.
On the last level, there's a room with four Shooting Stars ( The stars with Y on them). Run into the first star and aim for the enemies. Then, Air Jump and shoot for the enemies again. Keep doing this and you'll keep earning Big Pearls, which gives you a heart of health. This is the easier way to get the Galactic Hero Outfit. I thought that you can earn negative Pearls, but you don't. Oh, and kick that boss's butt for me. Please? I'm stuck on the part where you have to tap Y.