First you have to follow @sonyxperia on Twitter and then you must retweet the answer to the question that Sony is asking. Seems easy? That's because it is! Oh, and in order to answer the question correctly, you will have to watch the trailer for the aforementioned video game. That's pretty much it!
Head over to Sony's Twitter feed for all the details, and don't forget to read all terms and conditions prior to entering. Just keep in mind that the competition will run only through 12:00PM GMT on October 19, so don't wait until the very last moment to enter. Good luck!
source: Sony (Twitter)