Metro Last Light is the sequel to Metro 2033. Succeeding 1 year after Artyom, the main protagonist, uses a missile guidance system to shoot missiles where the 'Dark Ones' live. Thus destroying all of them.
Metro Last Light takes place in 2034. Russia's Community as a whole still resides in the Metro Underground from the Radiated Surface. The surface of the earth being destroyed in the past by a Nuclear Bomb and is still uninhabitable till this day. Only way to survive on the surface is with Gas Masks.
Artyom once again is sent out, by persuation of Khan, to find the last surviving 'Dark One' that survived the Missile Strike on their 'Garden'. He finds the 'Dark One' but is then lost himself trying to understand the destruction of his country when he was a child and comparing it to his missile attack against the Dark Ones a year ago. Thus later Artyom learns that the Nazi Reich plans to overtake D6, where Artyom's home is now. Using D6 and it's devices, with the help of a gas bomb, to flood out the tunnels of the Metro and kill everyone. The Nazi Reich finds themselves to be Genetically Superior to everyone else in various ways. So they believe the only way to rule over the Metro is to kill everyone. Not everybody in the Nazi Reich believes this. In fact some people were forced to help the Reich attempt to destroy D6. Including the Leader himself.
Overall I found the story kind of mediocre. Jumping all over the place and losing focus at many times during the game. Focusing sometimes on needless agenda's. Not fully explaining the story or what you would be thinking about at parts and closing out the ending so fast that you are sitting there thinking... What the heck just happened?
The gameplay is really this games saving grace compared to it's mediocre story. Choosing whether or not to either assault a group of enemies or to simply pass by them, the game has really expanded and simplified the use of it's arsenal and the use of it's equipment. From the many weapons that you can possess, to the many secondaries. This game gives you alot of variety to work with and to utilize in whatever situation you see fit.
Various things have changed between Metro 2033 and Last Light, but alot remains the same. At the Markets you can now purchase attachments for your weapons instead of purchasing a weapon with the attachments on. You can twist light bulbs out of their sockets to conceal yourself in the darkness which is really nifty for the stealth player in us all.
The game is so graphically enhanced you really feel like you've been sucked into the environment. Every little thing in the game seems to have alot of detail even when close up on an object. Now where there's awesome graphics... there are also glitches to follow. Mostly glitches with physics and characters not doing what they're supposed to do.
Overall I found this game quite enjoyable. The environment will lock you in and keep you playing until the very end but you will probably be disappointed by the mediocre story. The gameplay really helps out with that though as you face many different bosses, including several huge Rhino Like Mutations, along the way.