The band has confirmed that “Guitar Hero: Metallica” will include two very special guests: Lemmy from Motorhead and King Diamond.

“So hey, when we were thinking about this whole Guitar Hero thing, we thought we'd see if we could drag in some of our close friends into the game, too. Not only can you play as us, but we're happy to tell you that you can also play as our pal Lemmy from Motorhead!”
Lemmy says, "It's great to be in Guitar Hero with all these famous people and I'm really pleased to be in it with Metallica...but James is still taller than me."

"our other close friend is none other than King Diamond! King says: "It's been absolutely amazing to be a part of this Guitar Hero experience. It was quite a trip to re-record the song 'Evil' almost 25 years after the original recording took place.

The end result with four out of the five original musicians turned out so much better than I would ever have hoped for. Seeing my animated character take form was totally eerie in a very good way. It's so strange to see yourself animated in such perfect detail - cross bone microphone, Eye necklace and all. This game looks and sounds METAL all the way. HORNS UP!!!"

Source: Official Metallica Site | www.Metallica.com