From the site:
How To Play:
Think about a movie
Answer about 30 questions
Filmillion will guess the movie.
While you're there, read the About Game section where it explains how the website came into being, based upon an actual machine that was put into a cinema but was not a commercial success.
I had been looking for the movie The Genius Club (see post directly below this one) and tried it with the site. I actually stumped it...but the movie was "unknown" to them (and unknown to millions of theater goers, too, apparently). I then tried Dr. Strangelove and it guessed it within 30 questions!