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.
This floor plays sweet, relaxing music which allows you to relax and relieve yourself of stress. It also subtly brainwashes you into joining a certain mysterious organisation.
This floor used to be an indoor polo ground, but has since been taken over by bands of roving Greco-Persian War reenactors. One of their first acts was to cut a large hole into the floor, lined with black felt. This has lead to several fatalities, as unsuspecting people lounging in floor 299 are crushed by the heavily armoured reenactors, ironically relieving the victims of all responsibility.