RULES AND FEATURES
Game in the genre of tower defense. You command the armed forces of the United Nations, in the future, alien invasion and put the fate of the human race at risk. If the aliens will make their way to the surface of the Earth, the people are doomed. Will have to stop them through a system of orbital fortresses in space.
Build deadly defenses and don't let the aliens broke through your cordon.
You have 5 types of towers, each of them specializiruetsya on a specific role. You can sell a tower for 75% of its value to obtain emergency reserves of resources.
To begin the invasion, click on the words start. The next wave will be assigned on a timer, but you can run them faster for additional resources.
don't forget to upgrade the towers, they should rise to the maximum power of fire, power and range shooting, otherwise with many enemy machines you just can not cope!
You can play the game NATIONAL DEFENSE online 24 hours a day for free. It is no need to download and install it on your computer, and it is also not required you to be the registered user. Just ckick and enjoy. See also a set of related games below on that you might be interested to look.