Develop a iOS Game Application (iPhone, iPad)

I want the game to be part simulation and part arcade. I want to make money from purchasing the app and in-app purchases. Game should be shooter going through naval bases, finally reaching an island with treasure. There are enemies who want the treasure too. A battle ensues. There should be 50 levels with levels having to be purchased @ 69c every 5 levels and for other material. I want it to run on iOS only.