Well I'm on World 5 and the game is great. The challenge is balanced for the most part, it isn't ridiculously easy like NSMB: DS or way too hard either. It seems to have a perfect balance, along with lots of charm. The castles are well designed and I love how the game is ALMOST a re imagining of SMB3, to see the return of characters from that game made me smile. My only complaint is the world map, I feel it is too blah for the most part. The one thing I loved about SMB3 was that the world map was a character in its own way with secrets that could be accessed while on it. But with that said NSMB: Wii is a great game, and I love seeing the Koopa Kids back. Much more interesting then Bowser Jr. by a mile!