No revenue estimate for GOG — its rating/review counts don't calibrate to sales the way Steam's do. The Steam version is estimated at $1.5M — a different platform, not this one.

Niffelheim

Survive in the Underworld Warriors remain warriors even after death. Set out on the path to the last challenge and prove yourself to the Gods. In life you were never frightened by the cold, darkness and death, and you won't fear now. make sure you have enough provision, defend yourself and unravel the mysteries of these lands. Do not become forgotten Crush anyone who dares to attack your lands. Each fallen enemy brings you closer to Asgard! Bones, teeth, fur - use all of that as your weapons and armor. Build a fortress that will cover you from enemy attacks as well as help you destroy the attackers. The Death Priests will issue ultimatums. Will you comply or reject their orders and join the fight of their dead minions? Find a way out Collect all the pieces of the portal to Asgard. But be careful - these are fiercely guarded by mighty giants, undead and deadly spiders. Craft Brew various potions from mushrooms and slayed beats to become stronger. Cook the best dishes to feed all you friends. Brew poison that will kill the most powerful troll. Explore ancient caves Reach the very heart of the world to find powerful artefacts that will help you win the final battle. Find out what is hidden in the darkness.