While Guitar Hero: World Tour hasn't yet hit Australian shelves, there are reports from other parts of the globe that a hidden Easter Egg within the game hints at the next instalment in the series - Guitar Hero: Metallica.

Multiple sources appear to confirm this fact - with the twenty-seven second trailer unveiling the fact that Master of Puppets will indeed be featured in the game. It is unclear as to what other tracks will be included, but one might expect that we'll see the majority of the band's career represented - much like the recently released Guitar Hero: Aerosmith.

While no confirmation regarding platforms, release schedules or track listing has been released thus far, information on the Metallica instalment of the series is sparse. With the album Death Magnetic already available to those who own Guitar Hero III: Legends of Rock - it will be interesting to see if Metallica's entire back catalogue is made available for virtual guitar heroes, or whether only selected tracks will be available.

It will also be interesting to see if the track One will re-appear in Guitar Hero: Metallica, with the track already present in Guitar Hero III: Legends of Rock - one would hope so - as it can be considered one of Metallica's best tracks.

While a local Activision representative declined to comment on this rumour - there seems to be an increasing trend of companies revealing "new" games through teasers at the ends of "old ones", as evidenced by the BioShock 2 trailer found at the end of the PlayStation 3 version of the title.

Image from Guitar Hero: World Tour