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 $200.2K — a different platform, not this one.

Undead Horde 2: Necropolis

Become an Undead King and raise undead warriors from the remains of your enemies. Use your army of undead warriors to rebuild Necropolis after the vile attack conducted by the living. Take back your land, free the undead souls, and secure the future for the undead. Undead Horde 2 is a necromantic action game with elements from RPG, strategy, and hack'n'slash. Raise undead warriors of your choosing from enemy remains Command undead armies of over 100 units Rebuild the Necropolis and unlock new talents, new upgrades, and new powers. Find and unlock unique undead minions to raise Level up and become the savior of Necropolis Conquer the world and save the undead souls Raise minions of your choosing from enemy remains: There's a vast selection of unique units to choose from! Command the armies you've raised and claim victory over the living! Rebuild the Necropolis and unlock new talents, new units, and new powers. Gain powerful items to increase your might and the power of your army. Explore, conquer, and take back the souls the living stole from you.