First of all the BTTF films just might be the greatest trilogy of all time. Will we ever see three geniuses like Robert Zemeckis, Michael J Fox, and Christopher Lloyd, converge again? Doubtful. (Bob Gale (screenwriter), you were good too).

Secondly I wanted to add this to my "Puzzle Film" list to help demonstrate what I mean by Puzzle Film, for this movie is the anti-Puzzle Film (side note: this makes BTTF2 no less valid).

It is the anit-Puzzle Film for one specific reason. Do you remember when Old Biff steals the Delorean, takes it back to 1955 and the returns to the Future? Originally there was a scene where Old Biff gets out of the car (breaking his cane) stumbles a bit, and then disappears. The reason he disappears is because the future that Marty and Doc were in no longer exists because of what Old Biff did in the past (at least it does not exist for Old Biff who was then coming from new 1955, but it still exists for Marty and Doc because they came from the appropriate 1985... Plus, once Biff got all that money he probably would have killed himself with excess and never lived to be old).

When they screened the movie for test audiences, nobody understood why he disappeared, and this supposedly lessened their movie going experience. Subsequently, the scene was cut.

THIS WOULD NEVER HAPPEN IN A TRUE PUZZLE MOVIE! Scenes like that one are exactly what makes a good puzzle movie great. The audience should think, "why did that happen? I want to know more..." and then be inspired to do the proper amount of research either on the web or by listening to commentary tracks on the DVD.

Thus, I add this film to my list as an example of the anti-Puzzle Film.