| Metro: Last Light takes place in 2034, one year after the events of Metro 2033, following the ending of the original novel in which Artyom's missile strike against the Dark Ones — mysterious beings that seemingly threatened survivors living in the Moscow Metro — occurred. The Rangers, a neutral peacekeeping force that operates throughout the system, have since occupied the D6 military facility Artyom visited during the first game. This is a huge, and not fully explored pre-war bunker, and Artyom, now a Ranger himself, remains unsure whether killing the Dark Ones was the correct decision. Rumors of D6's discovery and its great riches have spread around the Metro; rival factions, such as the Soviet Red Line and Nazi Fourth Reich, hope to seize the bunker and its contents. Khan, a wandering mystic, informs Artyom and the Rangers that a single Dark One survived the missile strike. Khan believes that it is the key to humanity's future, and wants to communicate with it; Colonel Miller, the Ranger's leader, wants to eliminate it as a potential threat. Miller sends Artyom to the surface, accompanied by Miller's daughter Anna, the Rangers' best sniper, to kill the Dark One.
Metro: Last Light is played from the perspective of Artyom, the player-character. The story takes place in post-apocalyptic Moscow, mostly inside the metro system, but occasionally missions bring the player above ground. Combat alternates between the player fighting mutants and hostile humans. Areas are larger in Last Light compared to 2033, and the game encourages exploration by having multiple routes. The game offers more freedom to players, allowing them to utilize different tactics to combat enemies. It features destructible environments, in which certain objects, such as pillars, collapse after being shot. Numerous diary entries, written by Artyom, providing additional insight regarding the game's story, are scattered throughout environments for players to collect. In the post-apocalyptic environment, ammunition is a rare and essential commodity. Pre-apocalypse, military-grade ammunition is used as currency. Players can avoid consuming all the valuable currency by using lower quality bullets made within the Metros. Due to the scarcity of ammunition, a crucial aspect of gameplay is scavenging. The player can loot corpses and the environment for spare ammunition, as well as weapons and other items.
Redux introduced several changes:
- More realistic weapon handling.
- Slight lighting improvements.
- Slight texture and geometry changes.