With the explosive progress of mobile hardware, it's now possible to use advanced AAA graphics techniques that were previously only used on dedicated gaming platforms such as Xbox 360 and Playstation 3. However, there are fundamental technical differences that should be considered in order to achieve suitable performance and quality on mobile hardware. This session describes how mobile GPUs work under the hood, what caveats and work arounds there are, and how this affected the implementation of our visual effects such as the god rays and character shadows in Infinity Blade II and the mobile rendering engine in Unreal Engine 3.