The alien invasion is fast approaching and unfortunately you are the Earth's last hope. Defeat the fast approaching aliens and save the world. You are given one ship on the outset with no special weapons or abilities. Select the ship with the mouse and use the arrow keys to move it within firing range of the aliens. Use the collect gold to build towers to help, as well as upgrade your current ship in order to fend off the increasing number of aliens. Place your towers and upgrade them in a variety of ways with great strategy in order to fend off the aliens and save the world!