Leave the World Behind is one of those films that you either love (I did) or hate (my wife). First of all, I love Sam Esmail's work - just brilliant in terms of story, cinematography and overall "feel". I did not find it to be overly long and in fact, I was quite engaged throughout. It kept me trying to guess where it would go next. The ending, which seems to many people to be problematic was to me quite satisfying. Are there difficulties with the plot (the animals, the noise, the Tesla's?) Sure...But, if taken in the spirit of an allegory for modern life, it really did not matter. Humans are some messed up beings, who are their own worst enemies. Are all the questions answered? No. But that just added to the mystery. Personally, I like films that are "open ended" invoking questions, and making the audience think. I really enjoyed this film.