Those violins coming wildly but softly were a really cool touch to the main theme, I love what they add.
Then great musical narration with the return of this motif in the second track.
The choirs and deep cello in the third song add deepness to the story developpement. Well thought :)
The fourth track was a nice break with it's light instrumentation a calm vibe. It still maintain some tension, great for the solving puzzle part that you imagined!
The final boss theme wasn't that epic, but it managed to give me a strong heroic vibe while being very cohesive with all of the previous experiences. Nicely made :)