A disappointment as a serious Sci-Fi movie

Rating: 3/10 (18 November 2016)

I enjoyed it very much up until the last 20 minutes. Then it turned out to be a massive disappointment. It is very much like my experience with LOST, whose season one built up a huge hype ("wow I can't wait to see how these mysteries are solved in a reasonable manner!") and then the writers just waived their hands and went "mehhh, it's all supernatural".
Yes, "handwavy" is the keyword for this movie. The first half is great: it contains so many novel elements and thought-provoking details, and together with its slow pace, engages viewers in active and fascinating thinking and deciphering. But it is there only to make the second half more disappointing when you discover that its rendering of the translation process of an alien language is way too shallow; that there's little explanation for the alien's outlandish writing system; that there's no in-depth thoughts on what time is and how perceiving it as non-linear affects our world and causality (which is the main theme!).
For all the elements in this movie that are fascinating (How to translate an alien language? How does the alien's writing system work and *how* it changes people's thinking?), the writers could not find out a remotely satisfactory answer and decided to waive their hands and say "they work, dunno how". Not to mention at the end they played the time travel card, a recurring theme of which many great Sci-Fi movies offered their perspectives, but this one added none. It drew a picture too big for its own good.
So if you just want a movie with aliens in it, kind of thrilling, and in the end tells you a kind of moving story, Arrival can hit that bar. But It's a let-down for serious Sci-Fi fans. It has too little science in it.