Installed Deus Ex: Human Revolution Directors Cut a couple days ago. Been enjoying it, thats a good game.
Just ghosted the entire police station for fun, it wasnt even a requirement, but i decided all the policemen needed to get knocked unconscious and dragged into the ventilation shafts, because reasons.
It was tough to do without being noticed, took me a lot of tries to slowly pick em off one by one without anyone seeing.
I thought you got the "Ghost" level status from not interacting/touching/disturbing any of the enemies, but maybe I'm thinking of something else.