Heavy Metal is a map in Blacklight: Retribution set in a factory producing military hardware. It features close-quarters combat inside the facility, and longer-range combat in the roadways outside.
There are many gates located around the map that can be opened or closed by a small number-matching minigame. Opening or closing one of these gates can significantly change the flow of combat in certain areas of the map.
The factory in which the map takes place appears to produce much of the hardware seen and used in other maps in the game. This hardware includes the Spider Tank, Scorpion Tank, Rhino Hardsuit, and Panda.