Pirate's Curse will follow Shantae's efforts to retrieve the genie powers that were stolen from her. According to the game's reveal in the last issue of Nintendo Power, 30 Tinkerbats are behind the theft, and Shantae must team up with the pirate Risky Boots to retrieve the stolen goods. Pirate gear will help Shantae access new areas, such as the Bone Daggers that can be used on walls to create small platforms.
It's worth noting that Pirate's Curse is not the same game as Shantae: Half-Genie Hero, which WayForward recently launched a Kickstarter campaign for. While Pirate's Curse will be a 3DS eShop exclusive, Half-Genie Hero will reach the Wii U, PS3, PS4, 360, Xbox One and Steam if it reaches its funding goal of $400,000.
Update: This article initially stated that Shantae: Half-Genie Hero's Kickstarter campaign was targeting $40,000. The financial goal has been corrected.