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 $159.2K — a different platform, not this one.

Zombie Shooter

Where is the line between life and death? How far can human science go trying to understand this? Take part in the great battle to rescue humanity, and find out what's happening! The human race is in danger again. This time scientists could not cope the imminent threat and became monsters themselves. Crowds of zombie people filled the secret research base. The dreadful contagion is about to spread earth wide. Use the last chance to save the humanity from total annihilation! Find the answer to the main question - what caused the catastrophe? Who knows, maybe on the final stage you'll face something terrible...? Highly imaginative selection of zombies, with about 1,000 zombies on each map, showing up to 100 zombies simultaneously on one playing screen. Full-on-action male or female character. Red or green blood selection. Upgrade arms, improve the character’s skills, grab useful gadgets - from flash lights, to medkits, to battle drones and radar. After completing the Campaign mode, try your monster fighting skills in two additional game modes - Survive and Gun Stand. Only these modes will really show how good you've become.