Btw: This is the general discussion forum of SFML. Your question does not fit here at all 
Oh, schnap :shock:
Don't worry it does.
From the description of this sub-forum:
For talking about anything related to SFML that doesn't fit into the other forums
Also I would like to say that you should go with a more, evolving method instead. Write down what you want the player to experience when playing your game, just a basic view of it. Then try to accomplish that in the order it's written without doing anything unnecessary. Also this document is not supposed to be carved in stone. You are free to change it and do several different versions as you feel fit. The center of your development should be the enjoyment of the player.
This is a simplification of the Use case method in the agile development. Look it up if you are interested. It's what I use, though the complete version with User Story, Extracted features organized in a task list and so on.
