Toads Treasure Tracker is most probably known Super Mario 3D World. Toad collects stars and diamonds and has thus more or less (rather less) are tricky levels. Unlike Mario Toad can not jump. The game looks great graphically and it also makes a lot of fun. The game is very simple. I do not think the games should always be insanely difficult. Toad has micht very well maintained despite the fairly easy difficulty. In spite of a small criticism I can point each Wii U owners are recommended to look at this game times. A strong buy recommendation from me.
Addendum: By the end of the game the difficulty still attracts. Some levels are then including additional tasks not that easy to solve.