So I'm watching The Walking Dead, and being mildly diverted when I'm not getting angry, then suddenly I hear the oddest thing. Take a look at this brief sequence, where Rick shoots a zombie outside the police station, ensuring that Lennie James and his son will no longer be able to use it as a hideout:
Did you hear it? Buried under the sound of the chain-link fence is something that should be familiar to everyone who owns an Xbox 360.
Yup - it's definitely the 'achievement unlocked' sound effect.
Easter egg by the producers? Playful sound technician just dropping it in and hoping that no one would notice? You be the judge, because I've been too judge-y lately!