A listing for a new Picross game themed around The Legend of Zelda: Twilight Princess has been discovered on Nintendo’s servers by Twitter user Cellenseres. The game is apparently intended to be a My Nintendo reward and may be released on March 31st, 2016, according to metadata attached to the server entry.
The listing also comes with the 3DS icon and a screenshot of the main menu. There are options for standard Picross, Mega Picross, and Micross. Additionally, there are a tutorial mode and icons for Miiverse and settings.
The image below shows the HTML metadata containing the relevant information.