I've played it and I think it's fucking awesome.
As an old Metalhead I found the entire premise and opening scene is a great antidote to how shit metal has become, so I was sold on the opening cutscene alone.
The gameplay is great fun, some may call it a bit generic, but I love all those hack'n'slash type games, so it's right up my alley, and I found the controls intuitive and easy to handle.
The music is excellent and I love the presentation, like at the beginning how the intro to Children of the Grave continuously loops until you pick up the axe, then it unleashes it's awesomeness and you unleash your awesomeness.
The humour is a bit cheesy, but it fits in perfectly with the great pompousness that is Classic Heavy Metal.
I actually like it so much that I'm not going to buy it immediately (because it's released at the same time as Forza 3 which will demand a lot of my attention), but instead I'm going to get it as a Christmas present, because it's just a little bit special and it will be great to play with my brother at Christmas (he likes Classic Metal too and isn't much of a gamer, but I'd love to share the experience of going through the story for the first time with him).