Heavy Metal is Amber and Gustav Gale's boss theme in Sly Cooper: Age of Thieves.
Description[]
This music is meant to have a title with multiple meanings behind it that go with the overall tune. The title references both a sub-genre a metal music and the large mech that Gustav pilots. The tune itself, however, is a mix of techno and metal, with the two having more emphasis than the other depending on who Penelope is fighting. The first half of the tune is Amber's, having more metal music playing, and the second half is associated with Gustav Gale, with techno playing instead.