It's war, and this time it's too close to home. The Martian mission may be over, but the aliens haven't finished playing space invaders yet.

Extraterrestrial eyes have turned to a new target: they want Earth, and you're the one that has to say 'no'!

The action takes place across varied, lushly rendered Earth environments, and the alien assault force has grown more vicious than ever. Luckily, human turret technology has also advanced, and the ship weapons system provides a spectacular new way to eradicate invaders!