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 $27.6K — a different platform, not this one.

KINGDOM of the DEAD

KINGDOM of the DEAD is a pen and ink drawn horror FPS videogame where you play as Agent Chamberlain, professor turned Army General, now working for the secret government program known as GATEKEEPER, whose main purpose is to defeat Death and his armies. Features: • Close the Gates of Death, exploring 8 remote locations along the US East Coast • Unique black & white, hand-drawn visuals • 8 weapons, 22 enemies and old school bosses • Replayability like in the '90s, with different goals at each difficulty level • Customizable color palette Scour a world shrouded in shadows Send the creepy creatures of the army of Death back to hell Push on with your adventure, fighting the horrifying huge bosses you'll meet on your path