The robot aliens are attacking your city in Tower Defense Alien War. You have a responsibility to defend your people. To reassure you, though, you can overcome them since you are superior to them in strength. If you're prepared to wage war, do so immediately. 

The invasion of extraterrestrials has begun! They are not only extraterrestrial but also mechanical. You can rely on them to keep the bad guys out of your city. You must demonstrate your courage and battle to the death to save your people. In this game, you play as a hero whose mission is to stop a robot invasion of your city. Aim your weapons and prepare to fight! You won't be short of ammunition anytime soon. Use the mouse to point and click to fire the gun. Don't squander your ammunition; aim squarely at the robots. Eventually, the robots you face will be far more formidable than they were at the beginning of the game. With the money you've amassed, you've unlocked more potent weapons and abilities that will turn your rain of missiles into a veritable deluge. You can grab the coins by flying over them. As a bonus, you can speed up the rate of firing. Survival requires lightning-fast reflexes. It's game over if they take out the wall you're protecting yourself against before you can take them out. At the upper left of the screen, you will see how much health you have left. Get your weapon and get ready to fight!