A Shantae sequel was planned for the Game Boy Advance, and screens resembled a port with updated graphics. However, all news of the game stopped and nothing became of it. It is assumed to have been cancelled. As with the original game, Shantae Advance was developed by creator Matt Bozon on his own time. This may be part of the reason for its cancellation, as without an official corporate backing, finding a publisher would be prohibitively difficult. A DS and/or PSP game may be released in the future. – [info from Wikipedia]
Another Shantae project was originally in development for the Nintendo DS in 2006, but it was later canned for some reasons. You can check our page for Shantae DS 2006 for more info and screens! In 2009, a new Shantae was announced for the DSiWare and probably it uses some of the concepts from the unreleased GBA and DS 2006 projects.
Thanks to Icefire2626 for the contribution!