As someone who has played the Mario classics his whole life, I thought that this game was an absolute breeze. But I'm sure that little kids who are getting into the games will have a great time.
One of my main complaints with this game is that it tries too hard to be both Mario 3 and Mario World. It accomplished this task, but at a price. The game seems jumbled and incoherent, like it doesn't know what it wants to be. I have nothing against the modern Mario games, but this was just too much of the old. The whole time playing I was tempted to boot up the classics, which are way more enjoyable.
Veterans of the Mario games: Prepare to be disappointed by the fact its nothing new and too easy.
Newcomers: You are going to be in for a good time.