Also known as "Yacht Club Freedom Day".
http://www.nintendoworldreport.com/news/52194/shovel-knight-to-finish-on-december-10
Everything Shovel Knight is three weeks away.
The latest blog post from Yacht Club Games have confirmed that the King of Cards expansion, Shovel Knight Showdown (Wii U and Switch only), the three Shovel Knight boss Amiibo, a golden Shovel Knight Amiibo, and the Switch physical version of Shovel Knight: Treasure Trove will all release on December 10.
The Showdown and King Knight paths are the final releases from the original 2013 Kickstarter campaign.