Demon's Winter is a computer role-playing game by Strategic Simulations released in 1988. It is the sequel to Shard of Spring, set two hundred years after the events of the original, and featuring a game world thirty-two times the size of the previous one.
Following two hundred years of peace and prosperity in the land of Ymros, great numbers of aggressive monsters have suddenly appeared, devastating the region and its inhabitants. Five adventurers must band together in order to combat this threat, starting only with meager skills and supplies after a kobold attack on the now-ruined village of Ildryn. Ultimately, they must uncover the source of the beasts, as well as the unnatural cold that plagues the land, and ultimately put a stop to both.
Source: Wikipedia, "Demon's Winter", available under the CC-BY-SA License.