You have to destroy the aliens who come from another planet. Shoot some missiles to destroy them. Try to keep the maximum time possible in this survival game.
How to play to Alien invasion
Press START GAME. Use the mouse to move the tank, shoot the missiles and guide them to their goal. With every missile you can eliminate some alien spaceships, but there can only be a missile in the screen. Every 50 dead alliens, you win a tank.