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: The We Don't Go To Ravenholm.. level of Half-Life 2. One side loves it because it's mostly a break from the traditional FPS gaming. Others hate it for this exact reason.
Contested Sequel: Half-Life's Blue Shift and Half-Life 2's Episode One comes off as these.
Unlike Gearbox's Opposing Force expansion, Blue Shift didn't bring anything new to the Franchise other then a new armor system for playing as a security guard, and it's story turning out to be much shorter in length compared to the previous games. You don't even unlock all the weapons the original game had to offer.
For Episode One, it turned out to being much less content then the previous mentioned Blue Shift, bringing nothing new to the Franchise, and only lasted a short 5 chapters in length (with some levels spanning as low as just two overall loading-maps). Unlike Episode Two which was at least shipped along with Team Fortress 2 and Portal in the Orange Box. Episode One was a single game that was basically considered to be an overpriced DLC.
Demonic Spiders: The Overwatch Shotgun Soldiers added with Episode Two, then retroactively integrated into the previous two games. If they manage to close in on you, they can deal huge amounts of damage by using the shotgun's double-shell secondary fire. The game loves to put them right around corners where they'll gleefully exploit this.
Episode One and Episode Two have the Combine Overwatch Zombie. At first, it doesn't seem so bad, just a regular zombie with twice as much health. But then you realize that they can sprint, do more damage per hit, and most importantly, can whip out a grenade and suicide bomb you. That attack is nearly always a One-Hit Kill, and whenever you encounter a group of zombies at least one Zombine will use it, pulling out a grenade and sprinting at you. On the other hand, holding a grenade prevents them from sprinting, meaning if you're careful not to knock it out of their hand, and exploit the zombies' movements, you can use them against the horde, taking out a dozen zombies without ever firing a shot.
From the original Half Life: Those goddamn Alien Grunts, 8 foot tall alien Elite Mooks encountered 2/3 through the game. For starters,they were absurdly tough. Getting to close to them was nearly instant death due to their extremely powerful melee attack. They never, ever stopped firing their hive hands, even while absorbing an entire clip of 9mm rounds. There was absolutely no way to hide from them, hiding behind a piece of cover or around a corner was useless because their hive hands track you, and do the same damage per shot as the HECU's MP5 submachine guns. They were immune to damage on the armored part of their bodies. Worst of all, they attacked in groups, and that damage adds up over time, meaning almost every encounter with them would end with you a dead and them barley scratched. The only real way to deal with them was to use an extremely powerful weapon with rare ammo (i.e. the Rocket Launcher, Gluon Gun, Magnum, or the grenade launcher), or circle strafe while firing your submachine gun or shotgun secondary fire, hoping that they miss enough shots so that they die before you do. Basically, they were HECU grunts with twice as much health and homing bullets. Half Life: Source made a few changes to make them more manageable. The MP5 does more damage, they are briefly stunned upon getting hit, and they no longer completely deflect damage on their armored parts. They're still tough, just not as ridiculous as they were.
The problem with that is there is ALWAYS more than one, which will shoot you while you try to circle strafe their teammates.
Disappointing Last Level: The Half-Life Xen levels of the original game use to be the original Troupe Namer due to its terribly designed jump puzzles. Players do agree however, that the artwork for Xen is actually quite unique and nice to look at.
Subverts in Half-Life 2 where the fight through the Citadel with the powered up Gravity Gun is some of the funnest levels ever designed in gaming.
Dude, Not Funny!: According to Machinama's History Of Valve, when the original HL2 source code was stolen, Gabe Newell was actually more upset at finding the subsequent nude mods of the female characters having sex with the scientists.
People really like Adrian Shephard, to the point where Valve may bring him back, as most fans seem to believe he's always behind Gordon.
Also, DOG. Valve responded to his popularity by giving him a major role in the intro of Episode One.
Barney, to an extent. People have shown to be really concerned about where he is in Episode Two.
And, of course, the G-Man himself has gained quite a bit of popularity, especially through Garry's Mod.
The philosophical Vortigaunt and Nihilanth, simply because people love speculating about what they're telling you.
Father Grigori. Appears in one level, yet is one of the most popular characters.
Fan Dumb: One of the largest and most notable examples of Fan Dumb, considering that they tend to be pretty rampant across the internet and are not subjected to severe Fandom control on most boards. Say anything negative about the series as a whole will frequently get Complaining about People Not Liking the Show directed at you.And god help you if you so much as mention the Halo series to these guys.
Game Breaker: A grav-gunnable physics object resembling a boat hook and found on the beach during the "Sand Traps" chapter is this, both literally and figuratively. Literally, because at certain points, it can either crash the game or render further progress impossible and figuratively, because when fired at any organic enemy, up to and including Antlion Bosses, it's a guaranteed one hit kill. The harpoon found in the Lost Coast expansion behaves identically.
For a more conventional example, Opposing Force had the sniper rifle, and Half Life 2 had the shotgun. The sniper rifle may look like just another run of the mill rifle, but when you actually use it, it does 100 damage, more than the rocket launcher, with more common ammo to boot (though it was still uncommon). Combined with the fact that it was 100% accurate even without looking through the scope, it made many multiplayer games very, very easy. The shotgun in 2 seeks just like the shotgun from the last game at first, but it is also ungodly powerful. Ammo for it is everywhere, it will kill most enemies in one hit, it has surprisingly good accuracy, and it reloads surprisingly fast. Once you get it, there's no real reason to use anything else.
Opposing Force had the Shock Roach, an alien weapon you got off a Shock Trooper. It's very accurate, recharges infinitely, has a high fire rate, and does quite a lot of damage.
Genius Bonus: The series is full of references to scientific concepts (starting with the game titles), particularly quantum mechanics and cosmology. This game is where most people first heard about The Challenger Deep, Dark Energy, Singularities or The Calabi-Yau Model.
The teleportation theme seems to be a bit better researched than in most games, as well. It appears to be based on a wormhole principle, which, naturally, requires that Dark Energy everyone talks about.
Genre Turning Point: The first game led subsequent first-person shooters in a more complex, plot-oriented, realistic direction. Notably, this is where enemy AI started becoming more sophisticated than "run at protagonist while shooting."
In the beginning of the chapter Route Kanal, Gordon has to use a moving train as a bridge across the tracks. Since said train is also going under a tunnel, getting hit by the roof of said tunnel, a la Looney Tunes, will send you hurtling across the map, an even past the invisible barriers on the rooftops. There may not be much to see back there, due to those parts not being textured, but it IS pretty funny.
The original game, before the Source remake, has a pretty epic bug that can occur at the beginning of the We've Got Hostiles! chapter. If it's worked the correct way, the player can "glitch" the scientist yelling about the silo door to open up the security door; allowing the player to push the button himself and, as a result, skipping the entire chapter.
Hell Is That Noise: Players will learn to dread the hiss of the poison headcrab, as well as the whalecry of its zombie host.
Particularly terrifying is the distant howl of the Fast Zombie, which you will hear many times during your journey through Ravenholm. It makes a reappearance in Episode Two. Way to show that all is not right in where you're headed.
Hype Backlash: With a fanbase that treats Half-Life 2 as an absolutely flawless work of genius, those players who thought it was merely a good FPS game are often pushed into this.
Hypocritical Fandom: Gordon Freeman never speaks considering that creator Gabe Newell wanted to give Freeman a greater sense of embodiment, and quite a few people like him because of that. Unfortunately, some of these same fans tend to complain about other games with mute (or laconic) heroes, even if it's for the same reasons.
It Was His Sled: In the original Half-Life, the Marines are out to kill you, not save you. Pretty much every review spoiled that.
Memetic Mutation: What happened when someone noticed that one of the scientists working on the Large Hadron Collider bore a resemblance to Gordon Freeman. The Internet ran with it and went so far as to send a care package of items Gordon would need to save us all once the activation of the collider opened a portal to Xen. The G-Man was spotted too, so you know we're all dead.
Paranoia Fuel: Headcrabs are everywhere, especially when they leap out at you from vents when you don't have your flashlight on. Compounded when the sequel added poison and fast varieties of headcrab. An unofficial design principle for custom maps runs thus: "A headcrab in every vent is boring; a headcrab in one-fifth of the vents is terrifying."
Seinfeld Is Unfunny: Aw man, the first game suffers from this so hard today simply because everything it did was relentlessly copied by every single studio in the business. Modern gaming neophytes can have difficulty understanding how important it was, simply because they're very likely played a bunch of games previously which cribbed notes from what Half-Life did.
Scrappy Weapon: The Tripmines in the first game, the sub machine gun in the second. The tripmines were this because they were functionally useless since most enemies moved so fast, only being really useful on the last boss gargantua you face, on Xen. The sub machine gun in the second game seems powerful and fun to use at first, but later when the combine soldiers start coming in, it becomes painfully obvious that it is inaccurate and weak, not even scratching combine soldiers.
Half-Life 2 has "Lambda Locator" where you gotta find all 45 of the bonus stashes throughout the game. Looking for the last few will drive anyone crazy.
Half-Life 2's Episode 2 has some pretty nasty achievements.
"Little Rocket Man" for example, the lengths to which you have to go to get a garden gnome from the start of the game to the end of the game are obscene, especially during the car segment.
Even worse are "Get Some Grub" and "Neighborhood Watch." The former is hard because it requires you to kill each and every Antlion Grub in the game, which number more than 300, with some of them being very easy to miss. The latter is difficult because it requires you to complete the Boss Rush without losing any of the major structures. Completing the Boss Rush is difficult enough on its own, but with the extra challenge, it's nigh-impossible. To give some perspective, while 3% of everyone who owns Episode 2 on Steam have completed "Little Rocket Man," only 2.7% have earned "Neighborhood Watch," and a measly 1.7% have earned "Get Some Grub."
That One Boss: The Gonarch, which also doubles as That One Level. The same goes for the Nihilanth, and really, the entirety of Xen is "That One Level". The massed Striders you face at the end of Episode 2, as well. We've got Hunters everywhere, Magnusson whingeing at you constantly and the Magnusson devices.
Adrian Shepard of Opposing Force definitely comes off as this to those wishing for him to finally make a reappearance ever since the G-Man put him in indefinite detainment at the end of the game.
Race X, also from Opposing Force, comes off as this as well to those who thought this alien race was more fun and unique compared to the Xen aliens.
They Wasted A Perfectly Good Game Mechanic: Despite being made by Gearbox instead of Valve, Opposing Force offered a few gameplay mechanics not seen in any other game such as a grappling-hook with an unattached wall-barnacle and rope climbing.
Striders go from being the symbol of unstoppable oppression, to Boss in Mook Clothing, to two-hit takedowns over the course of the Half-Life 2 games (by the end of Episode Two, their miniature counterparts are actually considerably more dangerous).
Averted in Episode One, where a single Strider at the end is deadly beyond measure.
The Combine could fit this. They're a multiverse empire with futuristic technology who end up getting their butts handed to them by a crowbar-wielding scientist.
In fact, the military forces of the Combine, which were able to defeat the entire combined military strength of all of Earth's nations in seven hours, end up losing to a bunch of resistance fighters with scavenged weapons and no access to air support, mechanized armor, or artillery.