"2012 : Zwanzig Zwolf" is a sci-fi themed concept album of apocalyptic proportions featuring death, destruction, spaceships and more by US metal band Hanzel Und Gretyl

Decemberunderground is about the end of the world, according to a fan. One track is titled "Prelude 12/21", which is strong evidence on its own.

Pinnacle of evolution The end of linear time Progress or termination Cosmic ray mutation...

Doesn't mention 2012 specifically, but is about a pending end-of-the-world