So I'm doing some thread necromancy here, but I finally finished Memoria, after having first drifted away from the game after Chapter 2 for several months to do other things. I'm glad I went back to it, since things got considerably more interesting after that point, and the pacing also improved.
Is it just me or is the second chapter with Geron easily the lowest point of the game? I kind of see how they might've been shooting for contrast between both the protagonists and the settings - Geron's time is more low-fantasy compared to Sadja's era of adventure, while much of the point of Sadja's chapters is showcasing how intense and determined she is, which becomes even more apparent when set next to Geron who is something of a meandering whiner who complains about problems instead of facing them head-on. The second chapter introduces a secondary mystery which isn't actually all that important to the story and mainly just serves as an excuse to force Geron to talk to a number of said unpleasant idiots as well as engage in petty theft, which does get the point across that Andergast is a miserable place, but that could be accomplished without dragging it out for so long. It's just very... menial. The rest of the segments with Geron are all right, since they're pretty short and they have more to do with following up on Sadja's story.
Anyway, as it turns out, after that point the game does a fairly good job on concentrating on its best features, those being Sadja, the story as a whole and the puzzles centered on magic. The magic puzzles themselves aren't particularly sophisticated, but they're much more enganging narratively (whereas many of the other puzzles are clumsy busywork), and a lot more fun that way. The worst part of the game is dealing with tedious, obstructive petty antagonists who serve mainly as arbitrary roadblocks that don't actually contribute anything to the story. These are found mainly in Geron's segments, though unfortunately also XERXES! Sadja's XERXES! chapters XERXES! have XERXES! some. Ehh.
I have to say that the story has a great pay-off at the end, though. It really ties all the mystery elements together well, has a very nice twist-y ending and packs a substantial thematic punch, which is a very impressive achievement by any measure. There are awfully few good adventure games with a non-comedic story, so in that sense Memoria doesn't have much in the way of direct competition, but I'd say it's an impressive story by any measure.