Super Mario 3D World, for the Wii U, is a very unique game, that I think Nintendo spent good time on this.
The basic story line goes when Mario, Luigi, Peach and Toad go walking through the Mushroom Kingdom, when they find a clear pipe, and out comes a Sprixie, a fairy, to tell them that regular Bowser comes along, and captures all the other Sprixies, but then Bowser comes out of the pipe, and captures the last one. Then, they go through the pipe, into a different world, and then you start the game, in World 1-1.
Now, this is a bit like Super Mario 3D Land (3DS), but it adds some new powerups, like the Double Cherry, which makes you control 2 or more versions of yourself, and the very "famous" bell costume, which turns you... into a cat. Now I don't know what Nintendo was thinking about this, but it still is a pretty good thing, for speedrunners and novices alike.
Now, this game has a lot, I mean a lot of hard levels, but the hardest one, which is undeniable, is the level "Champion's Road". It took me 2174 (I counted) tries to do this thing, and I started this level in 2015, but just 3 weeks ago, I did it.
So overall, this is a really fun game to play with friends (If you dare...), and it has gotten really, really good reviews from websites (9.6/10 IGN.com, 93% Metacritic and 5/5 The Telegraph, 8.5/10 Spawn Point), but one thing that doesn't really stand out is that the main game is short. So I'm giving it 8.5/10.