Anime: Seikai no Monshou Tokubetsu Hen 5lkm

Not much to say here other than: this is just the 13-episode series cut and condensed down into a movie. There are some newish bits and pieces (very minor and inconsequential) but not enough to make it worth watching if you've already seen the 13-episode series, especially considering how much was cut out to fit it in this format.

In short: if you think the 13-episode series drags on too long then you might prefer this. For most people though, just the 13-episode series and skip this.