Instructions: For this you'll need to make sure your Ascend G300 is rooted and you must download ES File Explorer from google play store. Then you must edit the build.prop and change the Model to Desire HD from the U8815. Make sure you back up your existing build.prop somewhere safely before you do this!
Once you change the build.prop model to Desire HD restart the phone and then install. Otherwise you'll get a message saying, "Device is not supported. Please request a refund." Then gameloft will be tricked into thinking that your device is a Desire HD and will let you download the additional data via Wifi. And that's it you're done. If you want to change back. Paste back the original backed-up build.prop back to the system folder and restart. Your phone will be recognized as the U8815 (Huawei Ascend G300).
Hope I made it clear. There are videos demonstrating how to do this. It's very simple.