Yes it's true, I have all 242 stars and I got them without any cheats or using/looking at any guides or using the Cosmic Guide. About 4 or 5 of those stars were stupidly hard to get and the very last star is just evil in my opinion. The reward? Yoshi on a roof! Lol only kidding, you see Rosalina and then she joins you on Starship Mario like any other NPC and all she says is: "I want to give you my thanks" .... that's it. Lame. Oh actually, you also get a message and picture of all 242 stars sent to your Wii message board. Incredible... So what stars did you find the hardest? For me it was Luigi's Purple Coin Chaos in Mario Squared Galaxy, collecting the silver stars in Stone Cyclone Galaxy, one of the green stars in the same galaxy and The Perfect Run challenge in Grandmaster Galaxy (that one was a real bitch). My overall play time was 29:51:36 EDIT: Also at the file selection screen your icon will be sparkling and when you select it, you can see the title "Master of Galaxies!" with a platinum crown with a red jewel in the middle of it. Wow.... I feel throughly rewarded for my efforts lol. Further edit: Oh and you can also select Rosalina as an icon. OMFGWTFBBQ!!!111!!!!!!!!