The movie works mainly thanks to it's concept: A world with split gravity. Despite my expectations that this would become old quite fast they actually made a good use of it throughout the movie. The problem is that it's just not something exceptional (Yasuhiro Yoshiura's previous work "Time of Eve" is that). The plot should have been more about the world than Patema and Age or just less cliché. It was also hard to buy into the totalitarian regime and the villain was unrefined and frankly dumb. I make it sound a lot worse once again but it isn't a bad movie by any means.

For those who are wondering: this and the movie Upside Down (with Kirsten Dunst) have no connection to each other. It's a mere coincidence (and a four-part webseries which covers the beginning of this movie was released before the trailers for the latter).
Also, the "over-funded" Kickstarter for the UK + a few EU countries release is still going for another 16 days - https://www.kickstarter.com/projects/alltheanime/patema-inverted-ultimate-edition.

The concept of using inverted gravity is used pretty well in the movie. I liked the fear of being inverted as well.

This was kind of a cute movie. Very interesting concept and the ending was—at least for me—not predictable. The very end I did not necessarily fully understand.

The movie is like a bold attempt on the inverted gravity concept, and to be honest, it wasn't half as epic as i have imagined it to be but thanks to the smaller scale of the world Patema inverted took place, in terms of execution it's a more sense making and relatable story. The movie ends with some of the questions and logics unanswered, but the emotional aspects and stunning sceneries are enough to take viewers' focus off the rougher parts of the film.
I would recommend the film, but it's not a must see. if you want a more satisfying experience with the concept you saw in Upside Down, or if you have watched a lot of anime love story and still wants more, I'm sure it will be right for you.