I will try and not give away spoilers in this review except the basic plot of the game.
Metro Last Light begins nearly a year after Artyom launched the missile barrage that destroyed the Dark Ones lair, and has been inducted into the Ranger Order for his "heroic" actions. The Order itself has grown since the end of Metro 2033 and has established a permanent base at D6. With the Dark Ones vanquished the Rangers can focus their attention on settling disputes in the Metro. However, Khan, an associate of the Rangers, finds Artyom and tells him that he found a Dark One still alive in Moscow. From this point Metro Last Light begins and you embark on yet another journey to save the Metro... and hopefully this time for good.
Sounds like a recipe for a great game doesn't it? Well it is, in fact this game surpasses greatness. It is outstanding. 4A games really hit the nail on the head as far as atmosphere goes in this game. There are moments where you will feel anxiety when you see a group of Watchers skulk past you; you feel dread in the pit of your stomach when you realize you have sixty seconds to find another air filter or you'll choke to death in the radioactive miasma that covers Moscow. I would go back to areas I had beaten and play the level differently; all around the game is outstanding, but it is not without its flaws.
I played Metro 2033 on my PC and I loved it. Everything was responsive and if an error was made it was because I made it. The controls for the PS3 version felt a bit crammed together, and sometimes unresponsive. I felt the need to really mash the buttons in order for them to work. A personal nitpick was the voice acting. It was fantastic in Last Light, but I liked the voice actors from the first game more.
I have a great amount of respect for 4A Games they did not take the easy route and include multiplayer, or take away the things that made the first game so difficult and fun. If you want a game that challenges you then you should get th