I was planning on buying this, but the one thing every review says is that while the game is great, the main game is absolutely devoid of anything remotely challenging or difficult. This was my biggest peeve with New SMB on Wii and DS, fun games, but the utter lack of anything even slightly frustrating or hard made the games a total bore for me.
Why is it that Nintendo can hit it out of the park in this aspect with a game like Donkey Kong Country Returns where the game is a real challenge, but not to the point where it's a negative? I love DKC Returns precisely for this reason. Even the Mario Galaxy games have their moments of difficulty. Why does Nintendo feel the need to tone down the difficulty? Is it because they are trying to appeal to children and the casual market that doesn't want to be challenged? I wish I knew the answer, but I may end up avoiding this one as a result.