I'm gonna have to tackle 9-3 with friends. You know, the forced scrolling stage with all the fire-spitting Piranna Plants and Bob-Ombs. I can get the first two coins just fine, but by the time I get to the plant you're supposed to freeze to walk on and get through the red pipe (for the last coin) I've always taken a hit and lose the Ice Flower. Generally, the World 9 stages are either surprisingly easy or stupidly hard.