The artwork is definitely good, but I don't think I could call it outstanding. The music is background ambiance, again good but hard to call exceptional. The puzzles don't rely too much on pixel hunting which is a plus, but they mostly are the usual sort of point-and-click find objects and figure out where they go, with some parts requiring more in the way of puzzle solving to get through. The storyline is a mish-mash of stuff having to do with dimension jumping in a universe whose mechanics are only semi-explained, with the explanations coming mostly from notes of text. Considering each of those things individually, I'd give the game a rating of "reasonably good".
And yet I just played through all 10 episodes including this one, and all I can say is holy shit this series in general and this finale in particular is simply amazing.
You've somehow managed to create something that's far greater than the sum of its parts, and I'm just as baffled at how you did it as I am about the workings of the submachine in the story.