If anyone is looking to preorder this game then you can save £5 (I think it's UK only). just follow the instructions below. I got sent only 1 discount code but I'm not preordering, so first come first serve.
1. Head to www.hmv.com/starhawk
2. Select 'add to basket'
3. When you've finished shopping hit 'checkout'
4. On the 'order summary' page enter Z1STARHAWK under the discounts section and click 'continue'
5. Once your payable amount has updated with the discount, continue with the payment process