Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Essential Sci-fi Movie

This is one of the essential Sci-fi movies I think. Here you can see all the classics dilemmas on this kind of movies, and specially, how baddly could be the human.Also you can see how could be some time travel dilemma, how someone came from the future could change his own past and his own future.It's not a sweet movie but anyway you could enjoy it.