These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Broken Base: Fans are really split over how overwhelmingly samey the game is to Battlefield 3. Either they think it's a good thing for DICE to finally polish the working formula from BF3 to a mirror shine, or they think DICE should've really worked on Bad Company 3 or 2143 or at least shake things up a bit if they're still going with the modern day setting.
Complacent Gaming Syndrome: While the weapon balancing has so far prevented a "god gun" from showing up like in Battlefield 3, you'll still see Assault classes running a very limited pool of guns most times. Namely, the AEK-971, the ACE 23, and the M416, due to being a Jack of All Stats, ridiculously deadly in close range, and amazing at range with a fast reload, respectively.
With the arrival of Dragon's Teeth, we can add the Bulldog and the Desert eagle to the list. The former due to being one of the highest DPS guns in the game due to having the SCAR-H damage model and a moderate fire rate with the only cons being a small magazine, slow reload, and high recoil. The latter due to out performing the Revolvers of the game by having a faster fire rate, a larger magazine, and a faster reload than the revolvers while retaining the high accuracy and one shot headshot ability.
When people are using the recon class, expect about 75% of them to be using the SRR-61 due to its near non existent bullet drop (only the FY-JS has the same drop, but the poor minimum damage keeps it from being a viable choice at long range despite the rest of its stats being better).
Among Carbines, the ACE 52 CQB and the MTAR 21 are both extremely popular. The former due to it's high damage output (highest among all the carbines) and the later due to its blistering rate of fire.
Game-Breaking Bug: Aside from the (now mostly fixed) crash issues, a glitch spot on Operation Metro has been found that allows for people to get on top of the map, allowing them to shoot down through the breakable portions of the ceiling. If you thought Metro was bad before, now try enjoying it even a little after some dude drops C4 on your head from a completely untouchable, all-seeing glitch location.
The common reaction to the 17-minute gameplay trailer. Some fans really wanted Bad Company 3 or Battlefield 2143 over another shooter set in the modern day. Even fans okay with BF4 are underwhelmed at how similar it looks to BF3. There are many things that are direct lifts from BF3: The jeep, the knife animation, the models, it's all depressingly similar. While this could change, it's likely going to be identical to if EA had released another year of DLC and patches for BF3.
There's also the inverse: Some fans just want a BF3 without the crap, hoping that DICE learned a few lessons throughout BF3's many, many growing pains.
DON'T DESTROY THE BUILDING! note Some servers (due to a Game-Breaking Bug) explicitly either don't have Siege of Shanghai in the rotation, or if the map IS in rotation, explicitly tell players not to demolish the building as House Rules under threat of banning. And even in servers where it somehow works, players tend to agree not to blow it up as it makes the map harder to move around afterwards and less enjoyable to play.
The retail game itself gets called "Crashfield 4", since it crashes during map rotation, levolution events, and whenever the game feels like crashing.
Please send your feedback and bug reports to a popular YouTuber. note Many bugs and issues going as far back as the closed alpha were reported to DICE, only for it to still appear in the retail game. DICE officially responded to the bugs only after some popular YouTubers made videos about the issues, leading some fans to bitterly use this reply.
Operation Crashbreaker note The Dawnbreaker map had a glitch very similar to Siege of Shanghai, only instead of with a building, it was with an overpass that happened to be both destructible and have a capture point on it, very similar to the building in Shanghai.
Play the Game, Skip the Story: Much like its predecessor, the campaign and its narrative were panned to all hell by most professional reviewers and generally advised to be skipped in favor of the multiplayer.
That One Achievement: "Perfect Landing" in the "Second Assault" DLC requires, along with 10 hours of gameplay (easy) and landing on top of two very tall towers (slightly less easy but easily retry-able), requires a whopping kill streak of ten. Keeping a kill streak going for that long requires either a huge amount of luck, a really inattentive enemy team, and/or a private server.
That One Attack: The AA Gun's Active Radar missiles, which require no precision aiming or locking on to attack, simply aiming in the direction of a plane/chopper will cause them to automatically chase it down, and not only is the window to use flares/ECM small (at least they work against the missiles), but they produce no Lock-On alarm because they don't lock-on. Needless to say, AA Guns are seen as very cheap against aircraft (as in, Game Breaker levels)...especially if the user is just camping at the vehicle spawn area.
That One Level: Metro returns in the "Second Assault" DLC, despite being hated. The only reason people even play it is because it's an easy way to rank up levels.
It's Spiritual Successor, Operation Locker, is hated for most the same reason. Essentially, unless you get very lucky, whomever gets the central point first will hold it with a wall of grenades, snipers, automatic weapons, and rocket launchers, and will never let it go, turning the whole three entrances to the area into a meat grinder.
Scrappy Mechanic: Like a lot of large scale games with multiple types of vehicles and mechanics involved, there are a number of these, even from a limited demo:
The new vehicle ammo mechanic. Most vehicles are limited to a couple of reloads of the main weapons before having to wait a couple of minutes for it to regenerate. The tanks instead of having like 30 or more ready rounds in reality, now have half a dozen shells ready to fire before being forced to wait. Getting killed by an opposing tank without being able to fire a shot because you had just beaten away an enemy attack is incredibly frustrating. Helicopter combat can turn into a laughable dance with both sides having expended all their ammunition without effect. Their heatseekers take minutes to reload after firing just two.
The re-introduction of One Bullet Clips that many feel should be hardcore mode exclusive.
The game itself is much better optimized for the inferior Windows 8 operating system than it is for the much more stable and wider used Windows 7 OS.
Scrappy Weapon: While the balancing is noticeably better than the last game, there are still certain weapons that no one ever uses except when they're looking for an extreme challenge.
In the base game, there's the G36C, a Carbine. To put it bluntly, the gun doesn't do anything good. Its firing rate is slow, its reload is slow, its damage is unchanged from other carbines of significantly higher accuracy (like the AK-5C) or rate of fire (MTAR-21 and the like), and it has a weird issue with recoil. In general, this gun will lose firefights that should not be lost.
In the Naval Strike DLC, there's the unlockable Sniper Rifle, the SR338. It holds a unique niche in being the only real semiautomatic sniper rifle (all the others were re-classed as Designated Marksman Rifles), but it has a few... issues. Firstly, it is incapable of a one-hit kill (even a point-blank headshot won't do it). Second, it has bullet deviation after the first shot if you try and take advantage of the semiautomatic rate of fire, which if you want to kill someone, you must, for the reason stated before. This means that you can't even guarantee that the shots will land, which is the second point of a sniper rifle. And even if you tried using it as a DMR, its ridiculously tiny magazine and slow reload will leave the DMR class (as in, all of it) as a superior weapon.
You aren't likely to see many people using the QSZ-92, much less get killed by one. Despite having one of the larger pistol magazine sizes at 20 rounds and having fairly good stability, it does pathetically weak damage. Even up close, with an enemy at full health, it can take twice as many rounds to kill someone than it would with an M9 or MP433 and at a distance, you can forget about doing any meaningful damage to an opponent. There have been spitballs deadlier than whatever this gun is firing.
Tear Jerker: At the end of the campaign, the explosives fail at the worst possible time. As your team is suspended above the enemy ship, the choice comes to have someone drop back down with a pack of C4 to blow up the scuttling charge on the enemy ship. You have to choose to give the C4 to Hannah or Irish. If you wait too long, the USS Valkyrie explodes, killing Jin Jie, Garrison, Pac and everyone else you fought to save. If you choose Irish or Hannah, they will die, unable to escape the destruction of the ship. There is no other option. The final voice-over from the survivors confirm that it hits them hard no matter what you choose.
Unless you hated Irish. Then it becomes a moment to have a holy choir chanting to.
Most of the situation involving the U.S.S Titan. The crowner would be when Tombstone comes across several sailors trapped under a welded grate. They beg to get out, with Irish trying to help them out, only to Kovic to point out that even if they could help, they couldn't be helped in time. One begs you not to tell his mother he died this way as you walk away.
Unfortunate Implications: The ending allows for the player to kill the significant black character, the significant Asian female character, or an entire aircraft carrier (which has one of the other significant characters who is Asian), but the player character (who is presumably white) has to survive. Bravo, DICE.
This is slightly inaccurate. You have two people begging you to give them the explosive charges and sacrifice themselves to save a bunch of other people. The main reason you don't get to blow yourself up is that, quite frankly, its not going to be hard-hitting for the player. There's nothing to make the player really feel like he/she lost something in that instance. We'd probably still even get to witness the aftermath, so even less is lost. Hannah and Irish, on the other hand, are developed characters. You've spent the whole game getting to know Irish and the last few missions getting to know Hannah. Losing one of them should hurt.
As mentioned above, however, Irish is The Scrappy due to his complaining during the game, leading many players to choose him as a Take That, Scrappy!.
Irish's frosty attitude towards Hannah makes her bring this up in-universe, prompting her to ask Irish if he has a problem with women in the squad during the Singapore mission.
Win Back the Crowd: Considering the Broken Base and the lengthy list of faults Battlefield 3 had, DICE seems to be trying to make amends with Battlefield 4, judging by the multiplayer gameplay shown at E3 2013. Many Scrappy Mechanics such as suppression and infinite vehicle ammo have been rebalanced and overhauled, and maps look like they're actually designed for 64 players in mind.
Rebalancing (read: nerfing) suppression and the blinding effects of the laser sights and flashlights resulted in everyone playing snipers in hardcore mode.
Unfortunately some of EA's attempts to fix Scrappy Mechanics ended up as Scrappy Mechanics themselves.
The single-player campaign seems to attempt to reintroduce concepts seen in Bad Company (being able to select any weapon you want at supply crates, larger/less linear battlefields, visual cursor feedback when you hit an enemy, slightly more durable enemies, even a scoring system) which seems to be an attempt to move away from being a straight copy of the gameplay style of Call of DutyModern Warfare.