This is the same format as IGN's previous Need for Speed promo
Go to the website and request your code. Then redeem the code via the App Store/iTunes.
The process is even simpler if preformed directly on an iOS device:
- Follow the link to the IGN page
- Tap "Get My Code"
- On the screen that pops up displaying the code, tap on the code itself
- Your device should then transition to the App Store; input your iTunes Account password and the app will download