Each song grows gradually with more complexity and I like that. Usually I'm not one for these slower, more atmospheric entries, but I do enjoy the ends of songs when the buildup leads to some really nice sections.
Ashes of time and I forgot the world had my favorite sections at their respective ends with all the instruments. I also like how the final song calls back to earlier songs as a good sendoff.
Halfway through the final track when the strings came in was also really good as it gave the song more speed which I thought was something the OST needed dearly to give it more variety. I think more speed somewhere else in the OST would have been good though to really make it feel more complete. When all the songs have the same structure of buildup, it makes it feel less like an OST and more like a bunch of takes on the same idea.
The tracks were still good and varied enough, but their overall structure felt a tad too similar, at least to me in the context of trying to make a full OST.