Well, I once wrote a text adventure in Turbo Prolog as a project in
school. Unfortunately, TP isn't exactly the ideal environment (full
of frustrating limitations) and I never finished the thing. If you
want what I have (not good, but something), mail me.
I remember my main problem being to conjure up a good and general
interpreter.
With a more advanced Prolog, perhaps Prolog++, making an advanced
piece of IF should not be much of a problem.
/F