Game to develop first

Come up with cool game ideas is most difficult task. We have to choose only one from thousand ideas. So lets first decide what will be our gaming platform and what type of game we should develop first. In these days 2D platform puzzle is really interesting genre in gaming industry. So before going into 3D I would suggest to start developing 2D games first. Later we will move on 3D depending on the success of the first game. Please share your opinion on the same.