Yoshi's Island DS is the direct sequel to Super Mario World 2: Yoshi's Island, an indirect follow-up to Yoshi's Story, and chronologically the third video game in the Mario franchise. Compared to its predecessor, this game has fewer levels, remastered graphics (although still in "pen and pencil" style), new babies, and a whole new adventure. In this game, Kamek and the Toadies have kidnapped all the babies in the world. Yoshi, Baby Mario, Baby Peach, and the Stork team up and attempt to save the babies. Baby Donkey Kong and Baby Wario debut in this game.
Double Mario from Super Mario 3D World was actually the result of a mistake made by a staff member with the placement tool, which created two player Marios. The staff thought it was a good idea and decided to include it in the game.