Hey, welcome to the site pikazard. Generally when you make a storygame, people will give you advice by leaving comments on it (if you click on any published storygame it's the box to the right of the story description). That being said, we can always discuss it further here.
What is your storygame going to be like? Maybe we can help you with the difficulty level and maturity level based on your description of it. The story length is calculated automatically and it depends on a whole range of things (like number of words on each page, number of pages, number of links etc.), so you don't have to worry about setting that.
