The first thing that caught my eye about the Starbound soundtrack was the word "orchestral". Apparently, that's all you need to put on a soundtrack to grab my attention.
The second thing I noticed about Curtis Schweitzer's music was its length. The shortest track on the album (not counting the experimental tracks, which I'll address in a moment) is about four minutes long. That's a typical length for a soundtrack piece.
But many of Schweitzer's tracks exceed five, seven, ten … even twenty minutes. Nice, long, sweeping atmospheric songs that really, really make me want to play Starbound.
Take "Mira", for instance; this longest cue on the album clocks in at 20:05. It's a minimalist adventure, slowly unfolding as various cells (musical ideas) stack on top of each other and intertwine.
I also was drawn to one of the shortest tracks, called "Hymn to the Stars." In our conversation, Schweitzer explains how he stuck to traditional four-part voice writing rules (for instance). Schweitzer has written choral music in the past, which he says helped him write "Hymn to the Stars".
Included in the Original Soundtrack for Starbound is a list of "experimental" music. During the game's development, Schweitzer says the team considered doing a hybrid score, with orchestral instruments and electronics. As much as they enjoy these "experimental" tracks, the team settled on an orchestral sound for the game, but decided to share the music with the fans anyway.