"Looking at the top 10 selling Wii U games (2014 update), three games were released in 2012, six in 2013, and one in 2014.
The top 10 selling Wii U games have sold 17.17 million units. The top selling game, New Super Mario Bros. U, sold more than four million units. The top three titles sold more than two million units and the top six titles sold more than one million units. The entire top 10 sold more than 500,000 units."