It sounds like a song from a film. It's grand, adventurous and exciting. The harmony has this interesting way of switching from dangerous to wondrous, in a split second. I imagine a massive crack forms in a mountain as a giant machine rises from inside of it.
The quality of the instruments is very professional, like something from a Pixar movie. ( other then a very slight bitcrushy-type effect on the really deep horns starting at 0:37) but that is absolutely not enough to give this any less then 5 stars on the 'Quality' section.
Unfortunately I cannot say the same for the coherence to the theme, 'crystal castle'.
There's not really a crystal or quartz vibe to the song. There sounds like a very faint glockenspeil sometimes in the song, but it never takes center focus.
As for the castle-y-ness. This song absolutely perfectly strikes a grand sense of wonder. But it's not quite castle. It's an orchestral arrangement, and there's strings all over the place in this song. But castle-y-ness is a bit harder to achieve.
I look forward to whatever else you make, I just hope you stick more to the theme next time.
Great song regardless. 👍