Actually I have 3 different storylines for this game, but 7 days it really too short to put everything into it. So I just shorten it and pick up the core story of it.
Will add other storylines into it after the jam, with many more different 'choose your own adventure' options.
Also with some RPG elements or roguelike elements into it as well, such as HP, battle scenes, random heros, randoms monsters, etc.
The tool I used is https://twinery.org/