If you want to buy Darkest Dungeon, there are many places to do that including Steam and the Humble store, but through the Windows Store is NOT one of them. According to the developer of the game, someone has put a listing for the game up on the Windows Store and it is a very obvious scam.

The scammer, Balaji Chowdary, even uploaded an image from the game using a non-activated copy of Windows (see top image)! Some are saying that the $3.99 (USD) price simply provides users with a link to the Steam page for the game once purchased and run from the Windows Store. It could also very well include malicious content if run and for that reason, we will not be linking directly to the store page for it. If you do happen to come across it in the Windows Store, be sure to report it. Other fake apps uploaded by the scammer to the Windows Store include Lego Batman 3 Beyond Gotham, Sony Movie Studio Platinum, Watchmen: The End is Nigh, Warcraft III: Reign of Chaos, Farming Simulator 2015, and more.

This is just the latest in a long string of poor quality control on the part of the Windows Store.