You know the cast, the type of movie, possibly the director and the general theme. In this case you even know the prequel. Essentially you know what you're gonna get before you set a foot out of your house. The potential for a surprise is very limited with this type of movie. Essentially you already know that the only chance you'll remotely be able to enjoy that movie is by totally shutting down your brain. From this point on we can start arguing whether the movie is still offering anything!