Well, it's not a traditional hard - core science fiction movie. But it does have elements that can be related to the genre. The sudden transformation of the main character is like a scientific anomaly. It makes us think about what it would be like if such a thing could happen in real life. Tom Hanks is brilliant as always, and his performance holds the movie together, even though the science - fiction aspect isn't as prominent as in some other movies.
Yes, 'Big' can be considered a great science fiction movie in a sense. It has an interesting premise where a young boy magically becomes a grown man overnight, which is a sort of science - fictional concept. Tom Hanks gives an amazing performance, bringing the character to life in both his child - like wonder and adult - like responsibilities. The movie also explores themes like growing up and the challenges of adulthood in a unique and engaging way.