A new game stemming from Seiken Densetsu: Final Fantasy Gaiden is in development, according to a trailer highlighting a collobaration that sees characters from the game appear in Rise of Mana. At present no details are known about the title, such as platforms or how exactly the game relates to the original title.
Seiken Densetsu: Final Fantasy Gaiden is an action RPG spinoff to Final Fantasy, and is known as Final Fantasy Adventure in North America and Mystic Quest in Europe having been originally released for Game Boy back in 1991. Follow-ups went on to drop the Final Fantasy connection, becoming known as the Mana series.