From the preview:
"HM: Island of Happiness for the DS doesn't begin in the traditional manner. The player, who can choose to be a boy or girl, is on a ship taking a trip when a storm destroys it. The player ends up on a deserted island with a family of four and a merchant and his son. They decide to make the island their home, and the player is charged with being the food/revenue producing farmer.
Farming is totally different in HM: Island of Happiness. There are different weather conditions each day, and certain crops do better in certain conditions. Also you don't have to water every day, as some only need water every two days. Rice also is available as a crop (you plant it in spring and harvest in fall) and once again mushrooms and orchards can be grown."