The game takes place in a futuristic world where the player must defend against an alien invasion. The game environment is a series of terrain-based maps where the player can construct defenses and towers to fend off the extraterrestrial forces.
The player's goal is to protect the last remnants of human civilization from being overrun by the alien army. To achieve this, they must strategically place their defenses, manage resources, and make tactical decisions to maximize their chances of survival. The game runs directly in the browser, eliminating the need for a download or registration.