Unconquered Castle's original soundtrack has been released
https://store.steampowered.com/app/948910/__Unconquered_Castle_Original_Soundtrack/?beta=0
不落城-Unconquered Castle update for November 21, 2018
Unconquered Castle's original soundtrack has been released
View all patches · Build 3328280 · Last edited March 15, 2019 – 17:15:06 UTC by 
Wendy
Patchnotes via 
Steam Community