There is literally, ONE! review for this movie! ONE! ...well, two now. Let's get started.
Kantai Collection -movie sequence- is a hour and a half long movie that should be watched after you watched the anime. Or played the games. Or both. Unless you're a big fan of KanColle, you probably won't be as attached to the movie as much as the guy beside me during the release over in Indonesia, but I digress.
Here is a review from a person who knows about KanColle and has (tried to) play the games.
Due to lack of synopsis, I shall add my own. It's really short though.
==Synopsis/Story
In the middle of a sortie, a fleet finds a fleetgirl emerge from a Abyssal, followed by strange noises coming from the sea. Admiral is slacking off, so everyone else has to find out what that is. Also, the sea now has the debuff of "Rust", gradually damaging all the KanColle girls who has the Fleet Girl title.
It's really simple. You can consider it to be a OVA. Go buy the ticket to support the creators. They deserve it.
==Art
As expected of a movie-budget anime + literally one of the most popular web games in Japan, everything in this show is pretty. Very much so. The crying emotion on the faces of (one) cast was really well made.
Also, as one who has watched (way) too many anime, I can tell you that the use of CG was really well done. You won't notice it unless you look for it (I did it subconsciosly, and it was using the same 3D filter as Soul Worker, so it's really good.)
==Sound
Nothing special. I didn't really notice anything about it. It suited the situation but didn't really do much to add to the experience.
==Characters (Personal Rating: 7, Actual Rating: ???)
Did you watch the anime? Any number you give to the characters from the anime should be the same amount for the movie, since no one really developed from the anime. But we did learn that one girl never really got over a death(capsized). That was really sad to see.
==Enjoyment
Personally, It was okay. I mean, it's cool to pass the time but nothing I would really recommend to anyone unless they're a huge fan of KanColle. I expressed interest in the franchise, but that only got me so far. If I was watching this at home, I would've switched channels.
==Overall
It's fine. Go buy a ticket to support the creators. Who knows? You might like it as well.