Captain Toad: Treasure Tracker has been dated for a January 2015 UK release.
Nintendo revealed in its recent financials that the spin-off of the Super Mario 3D World mini-game would see a December release in Japan and the US, before coming to the UK and the rest of Europe one month later.
The specific day of release remains a mystery for now.
The Wii U puzzle game had previously only been vaguely scheduled for the last quarter of 2014.
The title follows Mario ally Toad as he navigates around 3D environments to hunt down treasure. Players manipulate the in-game camera to reveal new paths and hidden secrets.
Other Nintendo games currently set for release in the first half of 2015 include Mario Maker, Project Giant Robot, Splatoon and Yoshi's Woolly World.