Metro 2033 began as a novel written by a young Russian author named Dmitry Glukhovsky. It was first published in Russia in 2005, and it wasn't until five years later that it was translated and published in the United States. The Metro series consists of three books -- Metro 2033, Metro 2034, and Metro 2035.
The book follows a young man called Artyom who, along with other survivors, is dealing with the fallout of a massive nuclear war which has wreaked havoc across most of the World. Even though many in the city of Moscow, Russia, made it into safety in the underground train stations of the city, they are still being hunted and killed by mysterious creatures called the Dark Ones. It is a story of survival in horrifying circumstances!
The video game version of Metro 2033 was picked up by a Ukrainian development studio called 4A Games in 2006 and, in collaboration with Glukhovsky, they produced a first-person shooter horror game that followed the events from the novel. It was released in 2010 for PC and Xbox 360, but never made it to PS3.
Subsequent titles in the Metro game series include Metro: Last Light and the upcoming sequel Metro: Exodus. There is currently no release date information regarding the new game, but it is speculated that it will arrive sometime in 2018.