The original Shantae is a platform game created by Matt Bozon for the Game Boy Color. It was produced by WayForward Technologies and distributed by Capcom. Various Shantae sequels were planned for the GBA, GameCube and the DS, but never released. In the first Shantae Club newsletter (May 2008), Wayforward revealed some interesting infos about the DS version of Shanate: “In 2006-2007 we hit pretty hard, with a massive undertaking to redo the cast of hero and enemy sprites, and about half of the sequel’s backgrounds were created by the legendary Henk Nieborg (who then shifted to Contra 4). As you can see, the handheld market is again flooded, which is why we intentionally never made a formal announcement. But, you can see a first look here! Just be aware that this game exists as design, artwork, and tech only. Unlike the GBA game, there is no 2 hour long gameplay demo.”
In the website of Henk Nieborg we can see some of the concept arts that he was creating for Shantae DS.
We can also remember Shantae 2: Risky Revolution which was in development for the GBA, but later cancelled.
Thanks a lot to Martin Konrad for the link!
Update: In 2010, a new Shantae,probably based on the 2006 DS project , was released for DSIware. In video below we can some scenes removed from the final version.
Thanks to Icefire2626 for the contribution!