Anomaly Warzone Earth, the tower defense game where you’re the attacker, gives you the chance to defend our planet from an overwhelming invasion with a 60% discount until 9 August 2012 at 10:59 GMT.

The sudden, otherworldly strike against the Earth shattered the planet’s defences. Many of the world’s major cities were turned into smoking ruins. Upon them, the alien invaders built their heavily armed outposts. Things are looking very grim for humankind. But there’s still some hope. It will take a military mastermind to lead the remaining Earth’s forces and launch a successful counterattack, but it can be done.

Apart from the sleek graphics and flawless presentation this game looks just like every other tower defence game. But there’s a twist: this time you are the attacking party and the towers defending the battlefield belong to your alien enemy. As your units progress along their path, the hostile installations cover them with a hail of bullets. It’s up to you to manage your scarce resources, install upgrades, apply repair kits, and make sure that the human forces complete their objectives. If they fail, you’ll be the one to blame. After all, planning the best attack route is part of your job as the Earth’s last great military mind.

Get Anomaly Warzone Earth to plan your perfect offensive and launch a devastating attack against the aliens, for only $3.99 until Thursday, August 9 at 10:59 AM GMT.