We've seen two video game titles based around the Metro universe. Metro 2033 was an adaptation of the book with the same name. Metro Last Light was stand alone, later to be adapted into the book Metro 2035. The thing is Metro 2034 has yet to receive a video game. This in addition to the fact that most game series are released as trilogies. (By trilogy, I mean three installments.) I would love to see Metro 2034 adapted into a video game. Perhaps an open world style game. They touched upon it with the last two games, but exploration could be expanded. Recently, Metro Redux was released. This introduced the developers new game engine to Metro 2033. Revamping the game's graphical fidelity. Perhaps this is a sign that we might see 2034! The plot is very interesting and there's room for innovation with regard to Metro as a game. http://en.m.wikipedia.org/wiki/Metro_2034 Edit: Be aware that other authors made their own stories within the Metro universe. There are countless books out there that revolve round this sci-fi/supernatural/post-apocalyptic world. Adaptations could be made from these novels too. Edit: Most game series are released as trilogies. Which gives me reason to speculate. I understand that there are only two books released. 2035 was supposed to come out a few years ago.