The story is heavily divided, with multiple parts with their own plot. The parts are segmented into episodes 1-4, 5+7, 6 , 8-9, and 10-12. It winds up being all over the place, tending to be a repeating pattern of slice of life, preparations for sortie, sortie, miracle, and end sortie. Kancolle also tends to tunnel vision on whatever the current episode's plot is and forces the issue. The only overarching drive in Kancolle is Fubuki striving to become one of Akagi's escorts. Honestly, it's how the slice of life elements and combat elements are thrown into the pot together that really inhibit the anime as a whole.
Fortunately, the lead designer is great. He really brings to life the ships of so many different artists in one cohesive style. The best part is that the faces are drawn similarly enough to where you can look at both the anime and game styles and see how they correlate. The music is also solid and features a wonderful op and ed. The battle music doesn't quite pack a punch, but still fits thematically.
The biggest issue with the Kancolle anime is how the characters are handled. For some reason the writers decided that having all of the characters keep saying in game lines and slightly modified versions of in game lines was a good idea when it actually destroyed life from the characters. Look, I understand that the lines were probably put in because they wanted an easy way to convey the character's personalities, but it's possible to do it without resorting to such an uninspired method. I don't want to continually hear Hibiki's Russian one liners all the time. I want her to speak full sentences, and if Russian words want to be added in at that point, that's fine. Also, the fact that the admiral is never seen and never talks bothers me a lot. It just makes it feel like it's that way for self-inserting purposes, which just saps any joy from interactions with the admiral.
Even with all of its problems, I did enjoy watching Kancolle; however, I wouldn't recommend it to everyone. It is definitely something that you have to enjoy from the start, otherwise you would just be bored. If anything, episode 6 was the most consistent episode thematically and consequently the most enjoyable. As someone who has loved playing the game for almost a year and counting, this was definitely a disappointing experience. If you are curious about the anime, give it a shot, as you might enjoy it still.
