Super Mario Galaxy 2 (Wii) - Rightside Down Galaxy: Breaking the Laws of Gravity

This may look like a daunting and intimidating stage, but it really isn't all that bad. True, it may be disorienting at first, but it should be pretty manageable especially if you've played the first Galaxy game. I think the gravity gimmick in this galaxy is very well implemented and provides a nice challenge throughout it. The Comet Medal can be slightly tricky to get, but it should be easy to collect if you're patient around the Thwomps that surround it! :)