Sort of, yes. It's like being in a weird world where everyone you knew and were friends with disappeared...and you don't really remember if they were ever there in the first place.

But yes, it is sort of like playing a tabletop campaign; you're free to make up minor details, but if there's something major to see, feel, taste, etc. it'll be given to you and you can react accordingly.
It'll be much less spoon-fed than my first gargantuan post, I promise.

CASUAL EDIT: I might also mention that character interaction, of course, will be much less "You see a butt." "John is shocked by the butt!" and more...naturally flowing. I hope.