The tropical island is fun, but in order to unlock it, you have to pay the full amount of your house. Then the old mayor Tortimer (a turtle) will come and visit you to tell you about the island. I think it was the following day after Tortimer appears there will be a boat waiting at the dock with Kapp’n in it. You have to pay him 500 bells to get to the island and you can choose if you want to travel with other player or alone. Travelling with other player means it will connect you online so you can play with other players from all over the world.
Oh before I forget, you cannot bring any of your things to the island, except your bells! Once you are in the island, you can borrow most of the stuff you need from a Gyroid, such as shovel, net, fishing rod and so on. Then you can get fruits, bugs, fishes (even sharks) to take back to the mainland and sell or keep them, just put them in the basket near the reception in the island before leaving. On the tours, you can also earn medals every time you win, which you can use to buy stuff in the island.Over all, it is still a fun game and would recommend to a child who can read.