If you're reading PC Gamer, there's a good chance you're at least acquainted with Half-Life 2. For many, it's the unforgettable tale of that bit with the helicopter, or that bit with the zombies, or even that bit where that damn NPC wouldn't get out of your way.

Once, though, that story was very different. Okay, well slightly different. Different enough to feel weird and alien to our Half-Life 2 knowing future selves. Valve News Network combed through 2003's leaked Half-Life 2 beta in search of clues as to what might have been—pairing it up with information from Valve's own Raising The Bar.

It's not new info—people have been digging through the leak for some time. But as a Half-Life 2 fan, it's nonetheless a fascinating round-up of what could have been. It's not a huge difference, and in many cases the changes seem born out of certain levels being cut. Still, it's weird to peer into the alternate universe where Eli isn't Alyx's dad.

Much of the leaked content can now be used inside of Garry's Mod. Here's the Steam Workshop link, should you want to do that.

Thanks, Kotaku.

Welcome to our roundup of the best total conversion mods ever. Presented in no particular order, these are the mods that radically transform our favorite games into something different, with new and improved art, gameplay systems, locations, and adventures. Crafted through years of work, sometimes by large teams of volunteer modders, many of these mods have gone on to become PC gaming classics in their own right.

Here are the best total conversion mods ever made. 

Link: Sven Co-op on Steam

First released way back in 1999, Sven Co-op is still being both updated and played today. A cooperative mod for the original Half-Life, the mod allows groups of players to battle their way through the Half-Life campaign, where they'll find increased challenges and far more enemies, as well as new maps filled with puzzles and challenges. Over the years hundreds of new levels have been added along with new weapons, improved AI, and lots of customization options. Even if you don't own Half-Life, you can play it for free on Steam.

Link: A Game of Thrones mod site

For Game of Thrones fans, this mod is already at the top of your personal list or will be the moment you try it. It transforms CK II’s medieval Europe into the beautifully realised continents of Westeros and Essos and populates them with characters and events straight from the source material. Marry, mingle, or murder your way through the Starks, Lannisters and many other notable dynasties. Best of all, random game events will quickly spin the world into an enjoyable alt-reality of the fiction we’re so familiar with. This is an absolute must-have for gamers who are fans of the George RR Martin novels and the HBO series.

Link: Aliens TC ModDB page

Way back in 1994, this pioneer of full-conversion mods successfully recreated the 1986 sci-fi action film Aliens in Doom. It didn’t settle for just plopping face-huggers and aliens on a map, either: its custom levels mirror familiar locations and story beats from the film and even provide sound effects and voice clips lifted straight from the movie. Hearing Sergeant Apone through your headset reminding you to “Check those corners... check those corners!” not to mention Ripley furiously shouting “COME ON!” when climbing into her signature loader to do battle with the alien queen genuinely made me feel like I was part of the Aliens universe.

Link: Counter-strike ModDB page

You may have heard of it? The multiplayer Half-Life mod featured such team-based missions as hostage rescue and bomb defusal, each team with its own equipment and goals. With its quick rounds and exciting gunplay, Counter-Strike became an instant hit, and the community began creating maps of its own. Counter-Strike’s emphasis on teamwork and communication helped define a new genre of shooters, and the modders behind it were quickly hired by Valve.

Link: Nehrim site

Every full-conversion mod comes with a high degree of ambition, but it’s a truly special situation when the mod’s creators have the talent to match. Nehrim: At Fate’s Edge, created by German modding team SureAI over four years, does what the best full conversion mods do: reshapes the features that are lacking in the original game and provide hours of exciting new content. With original voice work by dozens of actors, big changes to several of the game’s familiar systems, and its own quests, story, lore, playable races, and a massive and beautifully designed new map to explore, Nehrim transforms The Elder Scrolls IV: Oblivion into an entirely new experience.

Link: Garry's Mod ModDB page

Plenty of games have a god mode accessible through console commands, but Garry’s Mod takes the idea to an entirely new level. A multiplayer sandbox limited only by your creativity, the mod has proven to be the ultimate tool for creating webcomics, videos and custom game modes, as it enables players to spawn objects and entities and pose them however they like. You can even play Half- Life 2 using all of the mod’s tools, turning Gordon Freeman from a simple gun-toting scientist into the ultimate expression of your will.

Link: Long War at Nexus Mods

Harder, longer, and with hundreds of changes to the base game, Long War extends XCOM's campaign, lets you play with up to 12 squad members at a time, adds new soldier classes, voice packs, weapons and technology, and lots of improved and completely overhauled systems. Long War wasn't just a hit with players but with XCOM's developers, who brought the mod team in to work on launch-day mods for XCOM 2, as well as create Long War 2.

Link: The Dark Mod site

This mod isn’t simply a celebration of the acclaimed Thief series using Doom 3’s engine, but actually an improvement on some of its features, especially the wonderful and engaging new lockpicking system. The open-ended stealth adventure lets you slink through a gorgeous, highly-detailed gothic steampunk world as you fill your pantaloons with loot and try to avoid detection. Most importantly, the mod comes with its own mission editor, enabling members of the community to create and submit their own custom levels and stories. The Dark Mod was released as a standalone game in 2013.

Link: Black Mesa site

It sounded like an impossible project: building the entirety of the celebrated FPS Half-Life in Half-Life 2’s Source engine, but after eight years of work by a large volunteer team of modders it finally became a reality. While it stops short of recreating the entire game (Gordon Freeman’s leap into Xen is the mod’s endpoint), it’s still a remarkable accomplishment. For Half-Life veterans it contains a mix of new design elements and familiar confrontations, and it’s a also great way to experience the ground-breaking adventure for those turned off by the dated graphics of the original.

Link: DayZ mod on Steam

In a game featuring starvation, sickness, and swarms of growling zombies, it still falls to other human players to provide most of the horror. While the standalone version of DayZ became a big hit in Early Access, the original open-world multiplayer survival mod is perfectly playable. The vast map and lack of global chat provide a feeling of intense loneliness, but the prospect of actually meeting someone else is a constant threat.

Link: Complex mod site

The name is certainly apt: this mod takes the real-time space strategy game and adds an almost absurd amount of complexity to nearly every single aspect. Alongside improvements to the AI, physics and graphics, the mod adds scores of new units and maps, constructible subsystems, deeper tech and research trees, and a diplomacy system. It even adds an actual calendar so gametime can be marked in years as in the Civilization series.

Link: Dota Allstars, a recent iteration of the original mod, worked on by IceFrog, who now works for Valve on Dota 2.

An exciting combination of RTS and RPG, the multiplayer battle arena mod for Warcraft III (based on a modded map from StarCraft) is a lot of things: simple to understand, difficult to master, and most of all, utterly addictive. In its early days DotA was a project that was passed from modder to modder, and like an unending stream of creeps it eventually spread through the gaming world to become a massive hit, as well as the first lanepushing game to have sponsored tournaments.

Link: NeoTokyo site

This team-based multiplayer mod for Half-Life 2 is set in a slick, futuristic cyberpunk city and features three different classes to choose from, each with their own distinct weapons and strengths. With lethally realistic gunfire and cloaking abilities available to some classes, NeoTokyo requires more stealthy and tactical play than many online shooters demand. Inspired by anime classics Ghost in the Shell and Akira, NeoTokyo also features an amazing and engrossing custom soundtrack that you’ll want to listen to even when you’re not playing the game. The mod was released as a standalone title in 2009.

Link: Mechwarrior: Living Legends site

Combining FPS action and simulation, this large scale multiplayer-only mod brings wonderfully realised Battletech mechs to life in Cryengine 2, though it began as a mod for Quake Wars. Tanks, jets, mechs and hovercraft strategically battle for territorial control in beautiful, varied, highlydetailed outdoor environments with full day/night cycles. The mod was so impressively made it was even sanctioned by Microsoft, who own the Mechwarrior franchise the mod is based on.

Link: Cry of Fear ModDB page

While it’s a standalone release now, Cry of Fear began as a Half-Life mod. It’s the story of a man who wakes after being hit by a car to discover his city is filled with gruesome monsters and his mind packed with psychological horrors. The mod has some interesting and immersive tweaks, such as an extremely limited inventory—and the fact that the game doesn’t pause while using it—that bring new challenges as you play through a disturbing, winding story with original animated sequences and multiple endings.

Link: Genkokujo ModDB page

The Sengoku period in Japan was a time of turmoil, political intrigue and near-constant warfare. What better time and place for a massive, openworld combat RPG built on the capable framework of Mount & Blade? The mod features actual clans and figures from Japanese history, new skins and armour types, new gunpowder weapons, and dozens of historically accurate locations spread across a map of Japan with twice the playable area of the original game. It also incorporates a number of other excellent M&B mods such as Diplomacy and Freelancer, which add even more great features.

Link: The Stanley Parable on Desura

You’re put in control of a clerk who suddenly finds himself completely alone at the office, but you’ll soon start to reconsider just how much control you actually have. While difficult to describe, the mod quickly proves to be a witty and insightful commentary on videogames, particularly the act of making choices. It’s also wonderfully narrated by a voice so soothing you’d like him to read you bedtime stories – if only you could trust him. It’s now a complete game with a lot more polish and an extended story, but the original mod remains a thoughtful, oddball delight.

Link: The Third Age on TWCenter

Every kid who ever picked up JRR Tolkien’s The Lord of the Rings novels has longed to step into Middle-earth, and one of the best ways to do it is with this mod for the turn-based strategy game Total War, capable as it is of portraying epic-scale battles. Third Age features over a hundred accurate locations and a dozen factions straight from the fiction. It includes custom units such as ents, trolls, giant spiders and wargs, and lets you play not just as heroes like the men of Gondor and the Silvan Elves, but also as the evil forces of Sauron’s Mordor, Isengard, and even the orcs of the Misty Mountains.

Link: Out of Hell ModDB page

As Donovan Ling, a lone cop investigating a garbled transmission from the industrial town of Grinwood, you quickly find yourself alone and fighting to survive a relentless zombie invasion. This mod is packed with astounding visuals of a city gone to hell, and a chilling original soundtrack accompanies you as you battle your way through more than 20 harrowing and atmospheric maps. Despite an arsenal of deadly weapons and melee attacks, you’ll never really have time to catch your breath.

Link: Natural Selection site

With one team playing marines and the other playing aliens, Natural Selection converts Half-Life into a multiplayer hybrid of first-person shooting and realtime strategy. It brought to life the concept of a commander in an FPS: a sole player who views the map in top-down fashion, giving orders, issuing supply drops, and managing the map in a traditional RTS fashion. The aliens have no overlord or shared resources, so must rely on communication if they want to win. Despite big differences in the two teams’ abilities and tactics, the mod remains a tightly balanced experience.

Link: Team Fortress ModDB page

Long before it evolved into a cartoony hat-trading simulation, Team Fortress was a mod for Quake. It originally featured five classes, later blossoming into the full iconic nine we’re familiar with today, and even provided a tenth class, the civilian, playable during VIP escort missions. Instead of just red and blue teams, certain maps for TF included two additional teams, green and yellow, struggling for map control and engaging in capture the flag games. The mod’s popularity led to a proper release and, much later, the Team Fortress 2 we know today, although the original mod is still played on a few servers.

Link: The Nameless Mod site

With a hundred new skins, sixty maps, custom cinematic sequences,and two storylines providing a hefty thirty hours of playtime, The Nameless Mod grew, over seven years of development, from something of an in-joke to a true mod masterpiece and Deus Ex fan favourite. Part homage and part satire, the mod sports thousands of lines of custom dialogue, tons of tweaks, and dozens of great new music tracks, not to mention books, newspapers and emails.

Aperture Science isn't the only one with a secret underground base. Deep in the Antarctic lies a hidden subterranean facility, filled with puzzles, lined with traps, and shrouded in mystery. Why is it there? What is its purpose?  Below the Ice, a mod for Half-Life 2, invites you to find out. Just watch your step.

The mod begins with you arriving in the Antarctic, where you quickly stumble upon the entrance to a facility buried in a glacier. There's a sign warning against trespassers, which feels a bit pointless. You've either traveled all the way to the north south pole and aren't going to turn around and go home because of a sign, or you're a polar bear penguin and you can't read anyway.

Entering this facility requires passing a bit of an intelligence test in a number of grid-like puzzle chambers. Many involve the simple pushing of buttons, though figuring out how to reach those buttons, and what those buttons actually do, can take a while. The chambers aren't particularly forgiving if you make a mistake, either. Prepare to be crushed, fried, or fall to your death if you slip up.

Once you've convinced the puzzle chambers you've got a brain in your head, you're granted access to the rest of the facility, which appears to have been abandoned. While exploring, you'll discover living quarters, science labs, and a series of offices. There, you'll begin to piece together the story behind the facility, which ties in to both the fiction of Half-Life 2 and Portal. It's not just a matter of walking around and reading notes: even though you've escaped the test chambers, there are still plenty of puzzles to solve to gain access to the facility's control rooms, observation chambers, and science labs.

The more you progress, the more the facility begins to reveal its secrets, and its true size. While you're navigating the place, unlocking doors, turning on lights, locating missing pieces of technology, dabbling in teleportation, and piecing together its history, also keep an eye out for a series of memory sticks. Find enough of them hidden throughout the mod and it will give you an alternate ending.

There's probably a few hours of play here, depending on your smarts. Some of the puzzles aren't particularly sophisticated: to progress, it's generally more important to carefully examine your surroundings for clues than to be some sort of 10th Level Puzzle Wizard. There's some decent music throughout, and while the map's set dressing is a bit plain, and a few custom textures are a little underwhelming, it's a nice mod if you're in the mood for some gently-paced puzzle solving.

You can grab the mod here and untangle the mystery for yourself. To install, extract the folder into your sourcemods directory (\Steam\steamapps\sourcemods), and restart Steam. Below the Ice will appear in your library. You'll also require Half-Life 2 and Source SDK Base 2013 single-player. You can find the latter by viewing your Games Library in your Steam client, selecting "Tools," and double-clicking it from the list.

November 16th, 2004 was a red letter day on both sides of the screen. The original Half-Life had redefined the FPS as an immersive experience instead of merely a series of missions, and no-one expected its follow-up to do anything less. Few were disappointed. In City 17, Valve created one of the most coherent and ambitious worlds ever seen in gaming—and if it looks a little primitive now, it s because so many since have followed in its footsteps. BioShock Infinite s opening for instance works almost entirely to Half-Life 2 s now dog-eared playbook, offering greater fidelity and a more exciting city, but recognizably the same style.

What Half-Life 2 really brought to the industry wasn t new ideas… though it absolutely had them… but demonstration after demonstration of how things both could and should be. Alyx Vance for instance was an effective sidekick and a fun character, but it was her ability to make a connection with the player through things like eye contact that elevated her above her others—something shared by fellow Source engine game Vampire: The Masquerade: Bloodlines, especially with characters like Jeanette and your pet ghoul Heather. She could shoot a worried look. She could smile, and have the smile go further than her lips. She could go directly from being your wing-woman to interacting with the world, from having conversations to fixing something, all as smoothly as Half-Life managed to never break perspective as you went from random lab geek to savior of two different worlds. She d even climb and vault over things instead of simply walking around the old fashioned way, easier as that would have been to script.

That sense of flow is what really defined Half-Life 2—sequences bleeding into one another to create the feel of an unbroken journey (give or take a loading screen). It was a game of smooth traversal around the maps, of combat bleeding into story, and each major section, most famously zombified Ravenholm, casually experimenting with the formula. Every cool bit offered something new and most left us wanting more, even if the radical shifts did take away much of the original Half-Life s thematic consistency. Every not-so-cool bit, like the dull start of Sandtraps (a vehicle section that paled in comparison to what Valve was able to pull off by Episode 2) was short enough not to be that big a deal, and something else was always on its way. While admittedly the story sequences are interminable by modern standards, the action was all about peaks and troughs that allowed both intensity and time to savor the craft.

On top of that came the details; a hundred things designed to be absorbed rather than directly noticed. The soundscape for instance, with the Combine announcements using medical terminology to describe uprising—Gordon Freeman as a staph infection —or the Combine s logo—an outreached claw almost, but not quite, absorbing a small world. It s a subtle detail, but one of many told through level design rather than audio logs or cutscenes. Others include visiting rusted playgrounds of a world without children, and seeing the empty seas that have left ships high and dry—the terraforming inflicted on the natural world mirroring the shift from old and human to new and alien that you see throughout City 17.

One of the most subtle, though much borrowed since, is the way that Valve tends to show new mechanics off three times—first with no pressure, then some pressure, and then for real to be sure the player has grasped and understood it, before it becomes an assumed skill. The gravity gun for instance. First you just move a solid box into position to meet Alyx. Then her robot Dog throws other boxes at you for you to catch. Then, it s zombie fighting time.

Speaking of fighting zombies, we can t overlook the physics engine—used in Ravenholm to let you hurl sawblades. Half-Life 2 was one of the first FPS games to go big on physics, for two basic uses. The first was, honestly, showing off. They were a novelty then, which came through in a lot of puzzles like pushing barrels under a platform to be able to cross it. Looking back, they re a little eye-rolling. At the time though, they were pretty cool. It s no secret that Half-Life 2 was at least in part a demo of Source, with these bits standing out even at the time as largely the equivalent of early 3D card lens flare effects. Cool, but gimmicky. When it showed them off, or put us in a vehicle, it was at least partly saying Look what we can do!

The big benefit though was creating a world that felt right, in stark contrast to the largely static worlds of the previous generation; of games like Return To Castle Wolfenstein and Medal of Honor. Again, yes, it s a bit showy to have a guard at the start insist you pick up and throw a cup into a trash can just to shout PHYSICS! What mattered though was that from there you both feel the benefit of them in every interaction with the world, big and small, and immediately start bemoaning their absence in any game that doesn t have them. The rolling and floating of flaming barrels in water. Debris flying off as it felt like it should.

It all added, in much the same way that the original Half-Life s responsive skeletal animation system instantly made conventional frame-based animations intolerably stiff. When Valve called its behind-the-scenes book Raising The Bar, it wasn t kidding. Half-Life 2 was an amazing game, but its crucial, lasting influence was less about the new things it did (as important as they ve been) as showing how the familiar deserved to be done.

Unforeseen consequences

Which of course brings us to its shining achievement—Steam. To sum up Steam s unpopularity in 2004 would leave no words left to describe ebola, lawyers, or Piers Morgan. And not without cause. It was buggy, it was ugly, there was no missing that Valve was outright forcing it down our throats out of nowhere, and the much crappier bandwidth of the day made being told to download games of this size almost offensive in its arrogance. It would be a long, long time before Steam even got close to the service that at least most of us know and love today, instead of its name just getting tacked onto the words ing pile of shit.

But. With Half-Life 2, Valve had a game that managed to get the necessary traction to create the service we know today, and while nobody would claim it s perfect, nothing else has done so much to legitimize and make digital distribution work. Much as it took Apple to break the music industry s obsession with DRM on MP3 files, it took Steam to show the whole industry that the game had changed. The idea that you d be able to redownload your games in perpetuity for instance was heresy to companies that at best wanted that to be another service. Being able to download them onto any machine instead of them being locked to a single PC, or maybe three, or five? That just wasn t done. Valve was the first major company to build a digital download service that people actually wanted to use, that made the experience of buying games online better. Without Half-Life 2 though, who would have used it? Without that audience, who would ever have agreed to let a competitor sell their games? Half-Life 2 didn t just give the FPS a shot in the arm, it changed the entire industry.

It wasn t a perfect game. It was far more a series of cool things than Half-Life s journey, it was heartbreaking to be taken out of City 17 almost immediately in favor of being consigned to the countryside, the story was primitive and a few of the set-pieces dragged on far too long. It held up pretty well for years, but looking back, yes, it s now a bit long in the tooth. Few games though have had a more lasting impact in so many ways, or can be deservedly held up as both paragon and pioneer. Fewer still have done it so well, they re still being copied a decade later.

Now then, Valve, about that Half-Life 3…

Every year, the month of November is notable for two events. The beginning of the month is marked by people muttering to themselves "Oh my God, it's November already?" and the end, in the U.S. at least, is celebrated by surrounding ourselves with cousins whose kids' names we can't remember and eating food until we explode.

This particular November is also notable for a milestone in PC gaming: the 10th anniversary of the release of Half-Life 2. This will no doubt inspire many nostalgic replays of Valve's landmark FPS, and Mod of the Week is here to make a suggestion about how best to walk another mile in Gordon Freeman's boots.

There's no shortage of full-conversion mods for HL2, and many of them are great and well worth your time, but today we're looking at mods that keep the original story intact as opposed to providing an entirely new experience. Enhancement mods, in other words. What's actually out there to improve the game?

Our first stop was to pay a visit to the simply named "Update" mod. Half-Life 2: Episodes One and Two provided a bit of a graphical upgrade over the original game, mostly in the form of better textures and slicker effects, but Valve never bothered to retrofit HL2 with these improvements. Modder Filip Victor took it on himself, but unfortunately, when HL2 was moved over to SteamPipe, it wound up breaking the mod. A fix, while promised in 2014, has yet to materialize. 

There were also rumblings about an ENB for HL2 that was sadly never released by the modder who did the same for the original Half-Life. No luck there. I also installed this ENB that purports to add depth-of-field and SSAO, but despite following the instructions I wasn't able to activate it in-game. Hurm. I'm zero for three.

That leaves us with pretty much a single option for souping up HL2 graphically: FakeFactory's Cinematic Mod. The name probably sounds familiar: it's been around for a while and there were a lot of complaints that it went too far: not just adding higher resolution textures, advanced HDR, new props, and dynamic shadows, but replacing the game's character models with new, completely different looking HD versions and adding music from the new Batman films.

While I agree that most of the new character models are tremendously off-putting and the music is a baffling choice, it's important to point out that Cinematic Mod is almost ridiculously customizable. You can run the mod without the replacement character models, leave out the new music, and tailor the look and even the difficulty of the mod to a high degree.

In fact, I'd recommend turning off a few things. The enhanced bloom is a bit much, and the head-bob made me nauseous (and I can't ever recall getting motion-sick from an FPS before). I enjoyed playing with the new weapons: a laser-dot pistol and some meatier machine-guns are fun, and iron sights and weapon recoil adds a bit more of a shooty feeling to the shooting (again, you can choose to play with the standard weapons as well). As far as the new models go, I actually liked the new Combine metrocops and soldiers the mod adds: they're bulkier and more dangerous looking without being a major departure from the originals.

As for the overall look of the mod, I liked a lot of it. It's slicker and shinier, and many of the new textures are fantastic. It does still go a bit far: I don't really need video screens flashing the word OBEY to get the idea that I'm in a dystopia, and some of the new graffiti textures are hardly subtle. Still, for the most part, it's very impressively done.

If you decide to use it, be prepared for a hefty 10 gig file, and torrent it or else you'll have to download it as sixteen separate .rar files (ugh). You can find it here, and here's a video detailing installation and configuration.

What else can you do to spice up your visit to City 17? Well, if you don't mind going full-on wacky, you can always try two previous Mod of the Week picks. There's Crylife (actually a submod for the high-octane SMOD), which gives Gordon Freeman the nanosuit from the Crysis games, and there's also gmDoom (actually an addon for Garry's Mod) that lets you play HL2 with weapons and monsters from Doom. You'll still be able to enjoy the story beats of the original game while spawning cyberdemons or running around with your cloak engaged.

Ultimately, though -- and I realize this is an odd conclusion for a mod column to reach -- I'd recommend replaying Half-Life 2 without any mods whatsoever. Yes, it's been ten years, and sure, the game is definitely beginning to show its age. But this mod enthusiast is happy to admit that some games just don't need improvement. 

Everyone still wants Half-Life 3. People feel its continued absence like a pain in the gut. Some people carry this weight around with them every day, and may well do so for the rest of their lives. Some people, when you say something nice has happened, silently whisper to themselves "Half-Life 3 confirmed?" 

This doesn't mean we ought to 'engulf' the lives of Valve employees, as a press release for a new crowdfunding campaign calls upon us to do. A ploy concocted by two interns at New Mexico ad firm McKee Wallwork & Co., the campaign is seeking $150,000 to organise a series of events and advertising sprees intended to persuade Valve to develop the anticipated installment. 

It's a unique idea - and it's probably not as dodgy as it sounds - but some of the wording is very problematic indeed, especially in light of recent harassment campaigns in the games industry. According to the press release received by VentureBeat, Half-Life fans have "never truly shown a united front", though "a little concentrated effort might finally get us what we want. The press release headline reads Indiegogo campaign to engulf Valve employee s lives.

VentureBeat reached out to the campaign creators Chris Salem and Kyle Mazzei, and this is what they had to say regarding the potential for harrassment. Obviously, lines like [engulf people's lives] is a little sensationalized to get people s attention, Salem said. But we think we re doing everything in a good-hearted way. We aren t going to have people camped out in front of Valve headquarters for weeks at a time. It s just going to be a one-day thing.

The IndieGoGo crowdfunding campaign involves the purchase of Google Ad Words, mobile billboards, a Valve doorstop campaign populated by Gabe Newell look-alikes and a concert. It's currently raised $36.