Simple! Easy! The rules are simple – if you had a skyscraper floor, what would you put in it? Why would it be special? Etc! 1st person does Floor 1, next Floor 2, and so on!
Post your posts like this:
Floor #
This floor is home to bla bla bla. Why? Because yadda yadda yadda yadda yadda. Also, it has yabber yabber yabber yabber yabber. It also has yeah yeah yeah in it. Nah nah nah.
Floor 1
This floor looks like an ordinary hotel lobby by day. At night the laws of physics become rather malleable.
Floor 741
This floor is the mind of a paranoid, emotionally unstable little girl with many issues. Who knows how long you'll be trapped here until you can advance?
A candy factory is located on this floor. Only humans on this floor are factory menager and a few visitors, since all the work here has been finished by robots.