Well, today i was playing Super Mario Galaxy and i finally beat the levels "Luigi's purple coins" and "Purple coins on the Battlerock". They were like, increibly difficult. If you have Super Mario Galaxy, and is stuck on the level "Luigi's purple coins", let me give you a tip. At the beginning, make sure you try not to touch many panels, and long jump off of them. Then run, and get the 1-up at the very corner of the platforms. then run to where his hat is, and get the Starbits that make a an L shape. by now, you should probably have 50 coins. just run around the place until you get 95 - 97 coins and then head back to where you started to get the star. Also Long Jump often to make the time limit. I also found that jumping, then to save yourselfby spinning, works pretty well. Good luck!