I just feel like putting the translations for the track names of the OSTs. Source is Wiktionary (how credible hahaha) and latin-dictionary.org .
Terrarum - ground, land; played during Rei’s journey in the arid lands
Oppidum - non-Roman town, referring to the humble town of the Phiroids
Vitae - lives, this is a pretty cheery track
Cantus - sung, chanted; Shiona’s theme?
Library - actually the only English-titled BGM in the list, Tipi’s theme?
Tristitia - sadness; the track played during a funera…
As for Kud Wafter… There are very few people here who have actually read it. The only people who come to mind who have read it are @HeliosAlpha and @Rin .