11 bit studios's tower offense classic Anomaly Warzone Earth is currently available at half its usual price.

The vanilla iPhone app is down to just 99c (from its usual $1.99), while the fancy Universal app for devices with Retina displays is down to $1.99 (from its usual price of $3.99).

In an inspired bit of role reversal, Anomaly Warzone Earth tosses aside the well-worn tower defence template aside and casts you as the attacking force.

Assaulting a heavily fortified position, you'll need to think strategically, exploiting your units' strengths to destroy enemy defences and deploying power-ups wisely to press home your advantage.

We simply couldn't get enough of Anomaly Warzone Earth's ingenious twist on tower defence, and in recognition of its sterling tour of duty we awarded the game an AppSpy 5/5 in our review.

Whether you're a strategy nut, a tower defence connoisseur, or just an avid iPhone gamer, you owe it to yourself to check out Anomaly Warzone Earth.