Oh, that was very hard for me at first. My best advice is to move quickly and not get hit at all, which can be a pain. Try to find shortcuts, such as jumping on Bullet Bills to reach a ledge faster. I believe that you should find all the red coins first and then the flowers. After that, go through the whole thing quickly while collecting all the red coins, flowers, and stars. With practice, it will be guaranteed that you'll do it!
