- Alternate Character Interpretation: Is Pavel a Well-Intentioned Extremist who genuinely likes Artyom and only betrayed him because he had to, or did he never see Artyom as anything more as a pawn to be used and discarded? Which is in full sync with the historical character he shares his name with. For one, the Dark One did say he was filled with sadness when he was fighting Artyom in Red Square. Not to mention the fact that he probably saved Artyom from execution during his time in Revolution Station, as well as technically allowing him through said station.
- Arc Fatigue: After you reunite with the young Dark One, you go through a long trek across the surface to return to Polis Station. And we mean long.
- Broken Base:
- Ranger Hardcore mode being as a preorder DLC. According to Last Light's community manager, this was insisted upon by THQ. By the time Last Light switched publishers after THQ's bankruptcy, they didn't have time to change the DLC plans before release. It's not much, but it is at least something that annoys the developers as much as the fans.
- The morality system, even moreso than in the first game. It is completely hidden from the player and requires one to perform counter-intuitive actions such as playing instruments during stealth sections in order to qualify for the "redemption" ending. Some people consider it annoying and illogical and would prefer a more generic, transparent morality system, if any at all. Others like it precisely because of how subtle and demanding it is. And then there are those who like the idea of a hidden morality score, but think that the requirements for getting a good ending are unnecessarily harsh.
- Complete Monster:
- General Czeslav Korbut is the brains behind the Red Line, a neo-Stalinist army that aims to conquer the Metro. Manipulating his superior Maxim Moskvin into poisoning the latter's own brother and political rival, Andrey, Korbut blackmails Moskvin with this information to obtain more control over the Red Line. Korbut would also test a deadly bioweapon on the peaceful station of Oktyabrskaya before attacking D6 to eliminate the Rangers and obtain more samples of the deadly virus, seeking to repeat the destruction of Oktyabrskaya with the entire Metro just to rule over what remains.
- Führer Yevgeniy Petrovich is the leader of the Fourth Reich, a neo-Nazi dictatorship dedicated to the extermination of those the Führer deems racially and genetically "impure". Those whom the Nazis don't instantly kill are sent to one of his concentration camps where the prisoners are tortured and worked to death, with toxic gases unleashed that would kill all the prisoners should even one be seen escaping. When protagonist Artyom Chyornyj and Pavel Morozov attempt to escape one of these camps, they see the Führer announcing his plans to attack D6.
- Lesnitsky is Korbut's mole within the Spartan Rangers, where he discovers and retrieves a deadly virus for Korbut. On Korbut's behalf, Lesnitsky unleashes this bioweapon on Oktyabrskaya while personally killing anyone who may have survived the virus's reach. Lesnitsky also attacks a church prior, killing more people and kidnapping Anna Mel'nikova, who he later uses as a Human Shield against her lover Artyom.
- Difficulty Spike: A few times along the plot relatively calm and slow paced sections are replaced with frantic fights to the death against packs of ninja mutant Nosalises. Since Watchers have randomized spawns and can call in more of their own kind if they are allowed to howl after spotting you, any surface level can have this.
- Throwing Knives. If you're willing to be lethal, it's entirely possible and actually quite easy to go through the entire game on a handful of the little wonders. Totally silent, hideously accurate, one-hit-instant-kills on humans and heavy damaging on mutants, and reusable. On both Ranger and Ranger Hardcore, you get to carry ten as opposed to the normal five, making them even more broken.
- Selling guns and explosives to the merchant at the start of the "Bandits" level will net Artyom hundreds of MGR. All it takes is selling the three guns you have, going through the level and killing/knocking out the level's enemies, taking their guns and returning to the merchant. Rinse and repeat.
- Genius Bonus: Upon reaching Theatre Station, Pavel refers to Artyom as "Stanislavski", which you'll probably miss unless you're knowledgeable on the theatre or the Russian arts.
- Good Bad Bugs: The Tower Pack in its DLC is an extended combat simulation done in spurts, making completing it (and getting its achievement) one of the hardest tasks in the game... unless you hammer the "Wear/remove gas mask" button at the beginning of a combat segment, which causes it to register success and end early. You can earn its achievement in about three minutes at most. This bug was not removed in the Redux version, either.
- Harsher in Hindsight: The plague infecting the Oktyabrskaya station caused by the bio-weapon that The Red Line unleashed on the station is stated to be a strain of the Ebola virus. About 6 months after the game's release, a massive Ebola outbreak took place in Africa.
- It's Easy, So It Sucks!: It's fairly hard to run out of gas mask filters or ammo on even the hardcore difficulties, quite unlike the first game. Not received well by some.
- Magnificent Bastard: Pavel Morozov is a cunning yet affable soldier of the Red Line who manages to escape from a Nazi concentration camp while taking Artyom Chyornyj with him where they bond throughout their journey. With Pavel's friendship with Artyom only surpassed by his loyalties to the Red Line, Pavel drugs Artyom and takes him to his superior, Czeslav Korbut, to be interrogated before being sent to Venice. Getting captured in Venice, Pavel is able to escape from his imprisonment before meeting with Korbut, where Pavel is assigned to unleash a bioweapon into the D6 bunker to weaken its defense line for Korbut's invasion, while ambushing Artyom upon seeing him.
- Sequel Difficulty Drop: Zig-zagged. While Last Light is much more forgiving than the first game in relation to stealth (there is now a clear indication of whether you are visible or not and a brief moment before you are actually spotted by the human enemies paired with a sound cue), which is what most of the game consists of, fighting mutants - nosalises in particular - has become a much harder ordeal.
- That One Achievement: Shadow Ranger achievement. Its description says "Complete the game without killing any Humans unless forced to", which is pretty vague. As it turns out, the player is only allowed to kill during Chase, Red Square and D6 levels (however it's still possible, albeit very hard, to knock enemies out in hand-to-hand), where the stealth option simply doesn't exist, while killing any human anywhere else fails an achievement and reloading a save does not fix that. The player has to start over with New Game. If you're particularly masochistic, try going for Shadow Ranger on Ranger Hardcore. Notably, Redux removes it and replaces it with several achievements for not killing on certain levels.
- The Woobie: While he is a soldier by this point and not an inexperienced Metro inhabitant, Artyom still takes more than a fair share of hard knocks. It doesn't help that at this point he may be a Shell-Shocked Veteran.
- Ugly Cute: The Dark One child is distinctly freaky looking. He's also totally Adorkable once you get to know him.
YMMV / Metro: Last Light