Nintendo are using Pikmin 3 to push The Wonderful 101 in Europe—specifically, the download versions of both games on the Nintendo eShop for Wii U.
Pikmin 3 is slated for release on July 26th for €49.99/£39.99, and buying that game will get you a 30% discount on The Wonderful 101 when it releases on August 23rd.
Note that you’ll only be able to avail the discount if you purchase Pikmin 3 between July 26th and September 21st. Additionally, you’ll need to buy The Wonderful 101 before September 21st as well, to avail the discount.
Update: There was an error regarding the release date of The Wonderful 101 in a previous version of this report. It has been corrected.