History YMMV / Left4Dead2

* ContestedSequel: No one can seem to agree whether or not ''Left 4 Dead 2'' is a better sequel or how the first game had a better atmosphere, amongst other things. Of course, it became a moot point after all the content from the first game is brought over into ''Left 4 Dead 2'' just two years after release as well as better support for custom content in the PC version, but that draw complains of the first game owners getting ripped off.

* HarsherInHindsight: Graffiti in the later levels of The Parish (as well as The Sacrifice comic) reveal that some survivors can be carriers of the virus and not show any symptoms. Fast forward eleven years and the real world suffered from the COVID-19 outbreak where it too can also be spread by people not showing any symptoms.
** Another example correlating the game to COVID-19 is in the Midnight Riders' staunch refusal to stop touring in the middle of the apocalypse, mirroring negationists who would not stop going out in spite of how easily the disease can be transmitted, which contributed to many countries having a high count of infected and deceased. That it came from a rock band also parallels Music/SmashMouth's infamous Sturgis Rally concert in which virtually no one wore masks or kept their distance (as well as Steve Harwell's "fuck COVID" rant), leading to a high count of infected attendees.
** Really, ''the whole game'' takes on a rather unsettling new look in light of the COVID-19 pandemic. The infection is suggested both in-game and in supplementary materials to be some kind of supervirus that mutates frequently, [[https://www.healthline.com/health-news/the-coronavirus-is-mutating-what-we-know-about-the-new-variants making it difficult to pin down and counter]]. Making things worse, CEDA (the in-game organization tasked with containing the infection) attempts to pass the whole thing off as "a flu." [[https://en.wikipedia.org/wiki/COVID-19_misinformation Does that sound familiar?]]

--> '''Ellis''':" Hey Nick, you and me outta get tattoos that says "Bros".

-->'''Nick:''' Ellis, did you get that girl's name? 'Cause I can tattoo it on your ass. She'll like that.

-->'''Ellis:''' Nick, you have a turd on your shoulder.\\

* RescuedFromTheScrappyHeap: Rochelle in ''The Passing''. While she had her fans, she had many haters before the DLC was released, due to her supposedly nondescript personality. But after it came out, most people did a complete 180 and warmed up to Rochelle thanks to her new lines. ''The Last Stand'' update also helped by restoring unused dialogue, of which she had the lion's share. The Community Update Team lampshaded this in the pinned comment on [[https://www.youtube.com/watch?v=bjnhx8Ip2Y8 this trailer]], which describes the restoration of cut lines as "Rochelle has a personality now!"

** Another patch broke Zoey's animations in the same level where instead of leaning on standing in place as she watches the other survivors escape, she stands in place and then suddenly ''slides across the balcony'', resetting her pose into her default "standing with my gun equipped" pose. It was fixed in the Last Stand Update, released late September 2020, roughly ''10 years, 5 months after the campaign is added to the game''.

* SequelDifficultySpike: In comparison to its [[VideoGame/Left4Dead1 predecessor]], there are many more spawn points for hordes, camping is discouraged by Spitters and Chargers, the new special infected are even designed to punish survivors that bunch up, rolling crescendos are much more challenging than the regular ones, and Realism mode adds another level of challenge even to the Expert difficulty.

** The Steyr Scout and AWP, ported straight from ''Counter Strike: Source''. Bolt-action rifle in a game about relentless hordes rushing toward the players? No thanks, especially where damage per second matters more and both the Hunting Rifle and Military Sniper Rifle were semi-automatic. This is only more apparent with the 2020 update unlocking these weapons for all servers and users, which is [[BlessedWithSuck probably an addition people will likely learn to loathe]].
** The SG 552 is a more marginal example; it shares its damage and fire rate with the M16, the weakest of the regular assault rifles, and gets a slower rate of fire when using its scope in return for the greater precision it grants (which ends up being a moot point for the AI, who don't use scopes). Worse, its lengthy reload animation doesn't match how fast it actually reloads - you're stuck being unable to fire it for a full second after you watched your character put the new magazine in. The Last Stand update fixes the reload issue by synchronizing the animation with the actual reload time though.

** The knife is simply too dodgy and slow to use effectively. Because the knife is small, it makes it difficult to hit enemies. Its slow swing speed also means you run a greater risk of getting hit in between each swing.
* SelfFanservice: Go look at how the Hunter, Witch, and Smoker look in the game. Pretty hideous looking zombies, right? Now go look how they are drawn in a lot of fanart. Notice any differences?
* SequelDifficultySpike: In comparison to its [[VideoGame/Left4Dead1 predecessor]], there are many more spawn points for hordes, camping is discouraged, the new special infected are even designed to punish survivors that stay ''too close'' to each other, rolling crescendos are much more challenging than the regular ones, and Realism mode adds another level of challenge even to the Expert difficulty.

** ''The Passing'' and ''The Sacrifice'' DLC campaigns are '''much''' harder than others in spite of being shorter.
** And in most every campaign that has been ported over from ''1'' to ''2'', there are alterations to increase difficulty. In some cases this is simply to adjust for the new gameplay elements, but they overdo it in some instances.
*** Most notably in the Terminal of Dead Air, what was once a panic event was upgraded to a Rolling Crescendo. However, the developers did not remove the normal crescendo event at the beginning of the level, resulting in this one having two crescendos, with one being one of the hardest in the game (you have to cover a lot of ground unlike in Dark Carnival).

* SequelDifficultySpike: In comparison to its [[VideoGame/Left4Dead2 predecessor]], there are many more spawn points for hordes, camping is discouraged, the new special infected are even designed to punish survivors that stay ''too close'' to each other, rolling crescendos are much more challenging than the regular ones, and Realism mode adds another level of challenge even to the Expert difficulty.

** "The Last Stand" campaign introduced the [[https://www.youtube.com/watch?v=eF0ZhqyVwQ8 METALIZED version of Tank Theme]] as you prepare to face ''two'' Tanks near the finale of the said campaign.

** "The Last Stand" campaign introduced the [[https://www.youtube.com/watch?v=eF0ZhqyVwQ8 METALIZED version of Tank Theme]] and prepare to face ''two'' Tanks close to the finale.

* AnnoyingVideoGameHelper: The survivor AI when it comes to healing. They will do their damn best to keep you going, but ignore anything else occurring at the moment. [[ArtificialStupidity Even if that means stopping you where you're standing, potentially condemning you, them, or some other teammate to death]]. Not to mention how they persistently try to heal you the second your health drops below 40. They adjust their "judgement" a little depending on how much temporary life you have, but not very much [[note]]For some incredibly stupid reason, the AI treats temporary health gained by pills and adrenaline shots as being ''half'' of that of permanent health, which often results in the AI wasting a health kit if they only have temporary health, rather than savoring that temporary health and using a health kit much later. The cvar "sb_temp_health_consider_factor 1.0" can be used to rectify this, but a mod is required to implement this without enabling cheats.[[/note]]. The only way to refuse treatment from them is to pull out a healing item (pills, adrenaline or your own medkit).

** The Last Stand introduced the [[https://www.youtube.com/watch?v=eF0ZhqyVwQ8 METALIZED version of Tank Theme]] while preparing to face ''two'' Tanks near the finale of the aforementioned campaign.

** The Last Stand introduced a [[https://www.youtube.com/watch?v=eF0ZhqyVwQ8 METALIZED version of Tank Theme]] to face ''two'' Tanks near the finale of aforementioned campaign.

** While The Last Stand Update initially garnered overwhelmingly positive reception from both the gaming press and the player base, it gained detractors over time as well. Recurrent criticisms are about some of the balance changes, some mods becoming broken with the update (mainly UI mods and Survivor Animations mods), and the bot AI debatably becoming less intelligent.

** The characters themselves left fans quite divided. You have those that prefer the survivors from the first game that were more down to earth while still having their quirks. Others prefer the sequel's survivors for being more joking in nature and more positive outlook on the situation and their more unique personalities, as well as being designed with the second game's mechanics in mind (the first set, upon being ported over, suffered many a SpecialEffectsFailure in animations and quirks).

** "Good Guy Nick" requires you to play an entire campaign from start to finish with two new players who downloaded the game during a free-to-play weekend. Due to free weekends for the game being few and far between as well as the tendency for this game (along with other Valve games) to be on sale for extremely cheap making the vast majority of players buying the game instead of trying it for free, the opportunity to unlock this achievement is very rare to the point that only ''2.3%'' of the game's playerbase even has it. Some players resort to using third-party software just to get this achievement out of the way as a result.

* UnintentionallyUnwinnable: In the [[CollectionSidequest scavenge finale]] of The Passing, the AI Director ''can'' spawn boredom hordes and specials if you take too long before talking to the first game's Survivors. If you do, activating the elevator will make the AI Director think you have lowered the bridge, and he will begin throwing the infinite Tanks and hordes at you... Even though you ''haven't'' lowered the bridge or even collected ''one'' gas can. And the best part? This doesn't reset if (when) you game-over. The only way to correct is to quit the campaign and start from the beginning.

* UnwinnableByInsanity: In the [[CollectionSidequest scavenge finale]] of The Passing, the AI Director ''can'' spawn boredom hordes and specials if you take too long before talking to the first game's Survivors. If you do, activating the elevator will make the AI Director think you have lowered the bridge, and he will begin throwing the infinite Tanks and hordes at you... Even though you ''haven't'' lowered the bridge or even collected ''one'' gas can. And the best part? This doesn't reset if (when) you game-over. The only way to correct is to quit the campaign and start from the beginning.

* DracoInLeatherPants: Nick gets slammed with a milder form of this in Nick/Ellis, which often overlooks his JerkAss tendencies completely in order to portray him as the perfect {{Seme}} for [[{{Wimpification}} Ellis]].

** Many people to this day hotly debate over the quality of ''Left 4 Dead 2'' with many people stating Valve hired n00bs for testing the game's bugs and difficulty. The same people even went on to say that they could do a better job in finding all the bugs. Two years later, Valve releases the Cold Stream campaign and all the original campaigns in beta to the public so that players can test the maps and send feedback to Valve to help improve them.

** Another patch broke Zoey's animations in the same level where instead of leaning on standing in place as she watches the other survivors escape, she stands in place and then suddenly ''slides across the balcony'', resetting her pose into her default "standing with my gun equipped" pose. Only the 2020 update managed to fix this.
** The ''[=L4D2=]'' survivors also lost their "falling-down" animations when they get incapacitated, which means as soon as they're knocked down, they instantly collapse to the floor without any transition. Thankfully, the 2020 community update re-added the animations.

* ContestedSequel: No one can seem to agree whether or not ''Left 4 Dead 2'' is a better sequel or how the first game had a better atmosphere, amongst other things.

* GameBreaker: The AK-47 can one-shot Commons on Normal difficulty, and unlike the SCAR and M16 it can be fired as a semi-automatic, one round at a time. In a game where ammo conservation is critical, that's a winning combination. Its main drawback is a wide grouping at long range... but add in laser sights, which give you near-perfect accuracy, and it effectively becomes a DMR, but without the typical "semi-auto only" downside. Even better, if you get your hands on explosive ammo, a full mag to a Witch will kill her without startling her. Of course, there's only one spot in the game where you can guarantee all of this put together, and it's on the easiest campaign.

* DemonicSpiders: The Special Infected. The mutation "Flu Season" turns the Boomer and Spitter into these, increasing the spawning cap for each to about four at a time and speeding up the Boomer from a cumbersome waddle to brisk walking pace.

** Taken to another level around Christmas 2013 where Valve made the game free to ''download'' for a day. Yes, anyone who downloaded the game during that time got the game for free and would own it forever.

** The Steyr Scout, which is stat-wise a Hunting Rifle with a god-awful fire rate. This unfortunately leaves it with the lowest damage per second of any weapon in the game, and if you're firing at a bunch of zombies attacking you up close, you might as well not bother. The AWSM has most of the same issues; even though it has higher damage per shot, its fire rate is even ''worse'' and as such only has marginally better damage output. This is only more apparent with the 2020 update unlocking these weapons for all servers and users, which is [[BlessedWithSuck probably an addition people will likely learn to loathe]].
** The SG 552 is a more marginal example; it shares its damage and fire rate with the M16, the weakest of the regular assault rifles, and gets a slower rate of fire when using its scope in return for the greater precision it grants (which ends up being a moot point for the AI, who don't use scopes). Worse, its reload animation doesn't match how fast it actually reloads - you're stuck being unable to fire it for a full second after you watched your character put the new magazine in.

** Don't forget that theory concerning the Witch and her fetus claws!

** "Good Guy Nick" requires you to play an entire campaign from start to finish with two new players who downloaded the game during a free-to-play weekend. Due to free weekends for the game being few and far between, the opportunity to unlock this achievement is very rare to the point that only ''2.3%'' of the game's playerbase even has it. Some players resort to using third-party software just to get this achievement out of the way as a result.

** "Swamp Fever" is disliked as a whole because there's a lot of water that makes you move slower, [[MarathonLevel the levels go on for far longer than any other official levels in the game]], the mud men's mud [[InterfaceScrew covers your screen]], and thanks to the flat terrain, its overall level design is generally not as interesting as the other campaigns. The finale has you fight two Tanks at once. Combined with the narrow terrain, staying out of the Tanks' reach is incredibly difficult, and this finale will usually result in at least one death even on successful attempts.

** The bridge finale of The Parish is the first Gauntlet Finale you're likely to face, and it's a doozy. Unlike in regular finales, zombies come in an almost constant stream, and you have to fight through them all to proceed. There are lots of cars for Tanks to punch your way, and the lack of railings means death by Charger is ''very'' likely. And just when you think you're about to head quickly to rescue, you have to navigate a somewhat-confusing path of concrete barriers... and there's yet another Tank which spawns during this section. Hope you've got a medkit and adrenaline shot on standby.

** Both "Death Toll" and "Dead Air"'s fourth chapters in the sequel ports, with the addition of gauntlet crescendos – infinite zombie hordes that only stop if you reach the safe room or die.