
I love Sora no Otoshimono so animation, sound, and characters were all great for me. The movie was not really a movie. It was almost no more than an episode length. This is not a joke. The first 36 minutes was a recap of Seasons 1 and 2 adding clips of Hiyori watching them on the sidelines with a few bits of added diaolog from her that were unimportant. You could pretty much skip the first 36 minutes of the movie and follow on perfectly well as to what was happening. Then after 30 minutes of the movie it ends and rolls to credits for an entire 30 minutes. (╯°□°)╯︵ ┻━┻
So that 1 hour 36 minunte time frame has just been shrunk down to an OVA episode of 30 minutes -_-' If you ask me that's an EXTREMELY bad movie. The movie was canon to the manga up till the end but the end implies the same ending as the manga. so it was just a little different to add more emotion I believe. Overall I wouldn't recommand watching this movie. Waste of my time and would be a waste of yours.
For me, Season 1 and Season 2 Recap is a must, for the first 40 mins, but it pertains to the background of the story from a different perspective, the theme/plot is great to follow up with a simple but heavy storyline it follows. This movie is a must-watch yet watching Season 1 and 2 of the series is a must so you can fully grasp the main series.