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 $500.2K — a different platform, not this one.

Whisper Mountain Outbreak

Whisper Mountain: Outbreak is an isometric co-op PvE multiplayer survival horror game where you and your friends must work together to escape the cursed fog-covered Mt. Bisik.  Explore abandoned buildings, fight monsters, scavenge resources, craft items, solve puzzles, and figure out a way to escape the whispering madness. STORY It’s 1998; a mining operation on Mt. Bisik inadvertently unleashed an ancient horror when they disturbed a ruin buried deep inside the mountain.  People started hearing whispers and seeing monsters when a mysterious fog suddenly appeared and covered the area surrounding the mountain. Now, you and your friends are trapped in the cursed Mt. Bisik. FEATURES Survive and fight the horde   Monsters will come in waves. Fight them off using a variety of melee and ranged weapons, use herbs to recover your health, and protect each other’s back! Co-op multiplayer madness   Teamwork is key in this race to safety. Communicate using a chat wheel, save downed teammates, and share the scarce resources you find. Explore, solve puzzles, and find a way to escape... together!   Work together to solve puzzles, find keys, unlock doors, and figure out a way to escape the cursed mountain. Uncover the town’s dark secrets and find the truth   Read notes, talk with NPCs, and learn the hidden secrets behind the cursed fog-covered town and the people that inhabit it. Claustrophobic, suspenseful, dark, and creepy atmosphere   A lingering fog, tight rooms, limited visibility, and limited resources.