This movie, and the sequels, put time travel into the correct perspective for modern Sci-Fi. Unfortunately, no one followed their example. To use the theory of time travel, they used actual theories that were being used at the time, modified them with some Hollywood style, and placed Marty into the age old problem, the Grandfather Paradox. This also introduced the popular idea of being able to better your life by changing one moment in the past.

At the end of the first movie, the creators added "To Be Continued..." just before the credits. This was meant as a light joke, as it was obvious that Doc Brown and Marty were destined to continue traveling the time line forever, solving problems. However, this was not taken as planned, as the fans of the movie were expecting the "planned" sequel at any moment. So, once learning of this, the creators decided to make two more movies and a sort of two part conclusion to the first.

Having no way of avoiding their previous mistake of going into the future (and taking Jennifer with them) they made the wise decision of making the entire future a joke. However, they are not very far off the mark, when compared with most predictions. Also, allowing the entire future portion to be a joke allowed the audience to focus on the plot rather than the environment, which was a major plus. The revisiting of the first movie was a nice idea as well, forgoing the original script which took place in the 60's instead, as this prevented them from needing to explain what has happened since last we saw Marty's young parents.

Going all out for the third movie, the writers went with a late 1800's rescue mission, with the twist of a time limit and life/death situations. Showing off the old west (and comparing it to the spaghetti western version) was a nicely done, epic conclusion to a single-made-trilogy of movies.

This is one of the few movies that had sequels that measured up to the original, and all three are well worth watching.