Enjoyable, but has issues
The developers recommend playing on the lowest difficulty setting (丁). I got overconfident and went for the next step up (内). I regret doing this as it led to me getting frustrated and quitting some 60+ hours in, because the only way to change difficulty is to *start over* from the beginning. Please keep this in mind.
Overall I did enjoy much of my time with the game.
Pros:
-Art and Sound are lovely, both for the setting and the characters (love Shigure and Kongou)
-High degree of faithfulness to the historical inspirations. Ship equipment is almost all based on things that really existed in WW2. Kanmusu have both stats and voice lines that directly reference the history of the ships they're based on, which is an extremely cool detail.
-Lots of room for exploration and discovery in building out your fleets and taking on new challenges
-Initial introductory experience is very good
Cons:
-For as much as the game does a great job of teaching you some things, it gives little or no information about other things. Combat and Construction are only just barely explained. Rules for traversing battle maps are almost completely hidden, allowing you to fail them dozens of times because you failed to meet an arbitrary condition that the game only vaguely hinted at.
-In line with the above, if you want to accomplish anything beyond the first 10 hours or so, you're going to spend a ton of time with a fan wiki page open looking up how to actually play the game.
-Leveling up new ships is incredibly tedious. Expect to have to watch your fleets do training battles with each other hundreds of times to level up new ships.
-Bad luck is common and infuriating. While you do have strategic control over how your fleets are composed and equipped, once you go into a battle area almost everything is left up to RNG. You will fail many, many attempts at clearing an area simply because of an unlucky critical hit on a Destroyer one fight before the Boss. Expect to spend a lot of time saving and reloading.
-Saving, loading, and reloading take *ages*. The load times are extraordinarily long compared to other contemporary Vita games.
-The game is also highly unstable and crashes frequently, so even though you don't *want* to save because it takes so long, you have to or else you could lose hours of work when the game freezes up.
If you're a fan of KanColle, or just curious what all the fuss is about, this game is certainly worth a look. Just set the difficulty as low as possible, have your phone or computer handy to look up construction formulas, and make sure you save often!