Movie Review - Is This a Puzzle Movie?

The first 20 minutes are pretty leisurely paced. The 30 minute mark is really where the movie starts to like reveal itself. Doc brown appears on screen 20 inutes into this movie. It takes 20 minutes, and then there's essentially ten minutes between when doc brown appears and when marty goes through time. That's the first half hour of this film. That is just a hair under two hours. But at that point, you don't really know what the movie is, right? If you're in, you're watching it going in blind. I'm trying to remember how i watched it for the first time.