Sunshine Islands has many of the same characters as Island of Happiness and the general rules of farming are the same but the introduction of a number of new pets and wild animals is a marvelous addition.
Sunshine Islands embroiders upon some of the themes of Magical Melody and Tree of Tranquility, two Harvest Moon console games. In Magical Melody, your character could use a Pig to search for Truffles. A Pig can perform a similar favour for you in Sunshine Islands. In Tree of Tranquility, you could befriend a variety of wild creatures who then might bring you special gifts. The wild animals on Animal Island, when befriended, may give you with special items as well.
In Sunshine Islands, you have a task of raising a number of Islands that sank beneath the sea. Each Island that you succeed in raising gives new options and introduces you to new characters. Mushroom Island is one of the Islands that you must raise. Here you can find a wide variety of wild mushrooms and it is here that Shea has made his home. When you have shipped 100 Mushrooms, you will experience a special Event on Mushroom Island. 'Gannon's Secret' is one of the secrets of Sunshine Islands in the form of a Pig who will find Mushrooms for you.
Animal Island is another one of the sunken Islands that you can raise. Wild Animals there include Ducks, Rabbits, Badgers, Mice, Sparrows and Monkeys. For all the players of AWL and AnWL who wished they could interact with the wild animals encountered in Forget-Me-Not Valley, Sunshine Island now gives that opportunity on Animal Island.
Here is Gannon's Secret, your introduction to your new Pet Pig: