And so, barring any future story DLC that might or might not come, I believe I have seen everything in Labyrinth of Galleria. All achievements get.
I feel like in most ways this was an improvement upon Labyrinth of Refrain. They've polished up the gameplay, done some interesting things with the classes, especially when you count both Alluna and Alstella versions of each class, and introduced new neat weapons.
I really like the idea of a weapon with a transforming element. Always picks the one most suited for an enemy.
And the story, just wow. They really went for some clever shit here. Honestly a little too clever for their own good sometimes, but they mostly pulled it off. And it was really neat to see how everything tied together towards the end. Once it got into the second "part", my mind was genuinely blown. As things progressed, so much of what I'd seen started to make more sense. They were kind enough to answer most of my questions, but still left enough intrigue to make me want to see more.