Enter GMG35-5BRU6-ZDRX7 on basket page for 35% off on XCOM: Unknown, Borderlands 2, or Chivalry. Having more than one in cart deducts 35% from most expensive item.
Also 25% off on "hundreds of other digital titles" which I take to mean everything else.
Source: http://blog.greenmangaming.com/2012/11/ ... oming.html
edit: good until Nov 16th 12:00 PM UTC