Pirate Kings is a boring children's game with the apparent objective of getting as much money as possible out of its users.
There is no concrete goal. You just spin a roulette wheel. Maybe you'll be rewarded with money to buy objects for your islands. Maybe you'll have chances to steal or destroy other pirates' objects.
Pirate Kings reloads the times you can spin the wheel every certain amount of time. But you can speed up the process if you pay with money. And that is how far your options go. Boring.