The First Dark Age of Wesnoth. Orcs are aggressively increasing their power on the Great Continent. However, not all of their campaigns were successful. You will witness the disastrous one. A small orcish settlement in the Heart Mountains is attacked by superior dwarvish forces. Orcs are doomed to be exterminated. Play this campaign and take part in the further story.
(Hard level, 12 scenarios)
Replays on the page: https://wiki.wesnoth.org/Player_UMC_Replays#Captured_by_a_Nightmare