Everything that the original Half-Life contributed to the first person shooter can be summed up in one word: context. Ammunition was found in ammo lockers, rooms and corridors were real spaces within the architecture of the Black Mesa facility, "levels" bled into one another, the story wasn't an afterthought. The significance of its sequel, however, is harder to fit into such a compact phrase. I can say this: Half-Life 2 is perfect. It remains the greatest shooter of all time, a paragon of thoughtful design and empathetic power. Gordon Freeman's tour through City 17 and environs is easily one the most timeless and unforgettable experiences gaming has to offer, one that entirely elevates the art of the video game and should under no circumstances be missed.
Perhaps Half-Life 2's influence can be neatly encapsulated. The word I propose to do this is immersion. Yes, the concept has in the days since HL2's release become a buzzword robbed of meaning by constant abuse. But think about how many developers have looked and continue to look to Half-Life 2 for inspiration. It is the standard-bearer for video game storytelling, because it tells its story through video game, not through movies or text or audio diaries. Half-Life 2 is the world's greatest first-person game in large part because it embraces the perspective and uses it to narrate the events in such a way as to make it nigh impossible to imagine the experience from a different point of view. Gordon Freeman is a theoretical physicist who, at the time of the first Half-Life, had just earned his PhD. After accidentally bringing about the Resonance Cascade (which tears open a portal to the alien borderworld Xen) and subsequently escaping from the Black Mesa Research Facility, Gordon is put into a 10-20-year stasis. He is the least likely candidate for savior of Earth, a glasses-wearing scientist who, as Dr. Breen (more on him later) mentions "is not some agent provocateur or highly-trained assassin..." and "was in a state that precluded further development of covert skills." He's a ridiculous warrior hero, and I mean that literally. Gordon's role as protagonist of the combat-heavy Half-Life series ridicules the entire concept of the video game hero. Even a "highly-trained assassin" wouldn't be able to do what Gordon is capable of doing. Valve realized that Gordon's feats of strength and survival are downright impossible by any means, so why the hell not make him a theoretical physicist? When Dr. Breen isn't venting and Eli isn't reminiscing, it's easy to forget about who Gordon is at all. This is not a failure on Valve's part; Gordon Freeman is a cipher, an HEV suit and pair of eyes that players adopt from the first train ride to the final explosion. More than in any other game, you become the main character. He never talks, never loses control (except when visited by the omniscient G-Man), and isn't graced with fancy animations. He's all yours, and this tight connection serves to heighten the believability that the game fosters.
Starting with the perspective, this believability works its way into nearly every facet of the game. Its presence does much to cement Half-Life 2's art direction as my personal favorite. Describing HL2's plot and setting is not impressive: aliens take over the world, you lead the resistance in an old industrial Russian city that has been repurposed as their embassy on Earth, making your way through tenements, canals, mines, highways, beaches, prisons, etc. It's the how, the approach taken to put you in this world, that's astonishing. The Combine is a militaristic coalition of extraterrestrial species that moves through cross-dimensional portals and subdues entire civilizations. There are the gas-masked Civil Protection, the white-uniformed cyclops Elites, the semi-organic sentient gunships, the lumbering multiple-story Striders, and more. City 17 is a lived-in, Soviet-styled urban prison. Even its walls, some bare brick, some painted yellow, some of Combine origin (cold blue steel monstrosities that slowly inch forward and crush whatever lies in their path), all look right. The surrounding environments are just as absorbing: the canals balance clear water and opaque toxic sludge, Black Mesa East is stuffed with surprising details (such as a jar of formaldehyde that holds the head of a Cremator, an enemy cut from the game), humble human outposts can be visited along the coast, the Citadel boasts some truly frightening alien architecture... As eerie and beautiful as the scenery is, at the same time it all feels absolutely real. By fusing reality with the otherworldly influence of the Combine and retaining a strong sense of authenticity, Valve was able to craft the best display of visual artistry I've ever seen in a video game.
Somehow, the game is nearly as memorable aurally as it is graphically. The blinking of a scanner, the mechanical whirring and whining of Dog, the compressed walkie-talkie squeal of a dying Metro Cop, the satisfying thwack and crunch of a crowbar swing, every sound makes a lasting impression and colors the experience.
Key to Half-Life 2's brilliance are its characters, which competitors could never hope to parallel, much less surpass. In the early days (2003), much was made of Half-Life 2's faces. In an age of dead eyes, plastered expressions, and mouths that would do no more than open and close, here was facial animation of such high fidelity and realism that passing spectators could honestly mistake it for the real thing. The "uncanny valley" is a concept invented in the 70's that pondered the point at which robots would come too close to resembling humans, making them overly creepy. As our technology has improved past the primitive 3D of the mid-90's, this question has been posed to video games. How long will it be before video game characters fall into this uncanny valley? Are we already able to reach it? And if so, how do we avoid it? Whether they stop just before or sail right past I don't know, but the characters depicted in Half-Life 2 look like real people without looking wrong. The faces, body language, costumes, and voiceovers for Alyx, Eli, Dr. Kleiner, Barney, Colonel Cubbage, Dr. Breen, and the oppressed citizenry all work together to breathe life into these digital ragdolls. Half-Life 2's script is intelligent and economical, imbuing everyone with just enough personality and throwing them all at least one savory line ("I still have nightmares about that cat..." "What cat?"). While there is not a single lackluster personality, Alyx stands out as one of the most developed and likable in interactive entertainment. She appears to be your typical ass-kicking sci-fi heroine/companion, (and she is) but she's so much more. With a respectable and charming design, a perfect voiceover from Merle Dandridge, and highly capable AI, I don't think I'm alone in saying that it's a treat to have Alyx around. Half-Life 2, thank God, is more focused on character than plot (remember, it is sci-fi), and because of this, the player is able to invest in the story and its participants; it may be the only FPS in the world that makes me care.
The most noticeable innovation and biggest bullet point for Half-Life 2 in 2004 was its physics engine. In the 3D video games of yore, physics were either all but absent or thrown in occasionally purely for visual splendor. Half-Life 2 redefined physical gameplay, taking what could have been a gimmick and sewing it so meticulously into the very fabric of the experience that without its presence, the game would fall apart. Objects have appropriate physical qualities, some of which are for detail (how far a leather boot can be thrown) and some of which are gameplay-essential (being able to break a wooden crate). The heightened interactivity that real physics produce even allows for new approaches to atmosphere and storytelling. In the starting train station, a Metro Cop stands in front of a gate, with a garbage bin to his right. When you near the gate, he uses his stun baton to knock off an empty can that was standing on the edge of the bin. "Pick up the can," he says. You press the action button to lift the light aluminum object. "Now, put it in the trash." A couple of options are available to you at this point. You can obey his orders, which will lead him to chuckle and let you pass. Alternatively, you can throw the can at his face, causing him to chase you around and beat you with the baton, but allowing you to pass through the gate nonetheless. I enjoyed Half-Life 2 immensely even before a certain point is reached, but afterwards, it's almost hard to imagine how. I am of course talking about the acquisition of the Zero-Point Energy Field Manipulator, or Gravity Gun for short. Able to pick up and launch any object of reasonable mass with the press of two buttons, the Gravity Gun is gaming's greatest toy. Employed equally in combat (returning grenades, using barrels as shields) and puzzles/navigation (removing obstacles, feeding barnacles), the technology is so awesome that it practically gets its own level: none of us can forget Ravenholm.
The zombie-infested wonderland of dismemberment that is Ravenholm is certainly special, but it's not the game's only memorable area. Half-Life 2 is graced with some of the best linear level design ever. In Gears of War, Marcus Fenix will move to a courtyard, hold off a wave of Locusts, and advance from cover to cover. In Call of Duty, soldier #8,954 will muster up the courage to mow through his army of assailants before their infinite respawn checkpoint is breached and the attack ceases. In Half-Life 2, Gordon Freeman uses every skill at his disposal to navigate thoughtfully-constructed environments, whose challenges never appear artificial, while taking out any Combine imperialists or headcrab zombies who get in his way. HL2 might be the only game I can play the whole way through in my head, based entirely on its unforgettable "levels" and flawless pacing (I was originally going to devote a whole paragraph to the pacing, but I'll just say that it adds a lot to the game's quality, as if that was needed).
Half-Life 2 would still be in my top 5 if it were simply a masterpiece of storytelling and game design. But, on reflection, it's more than that. There are deeply ingrained, though subtle, themes here that are continuing to be explored in the episodic sequels. Dr. Breen's televised propaganda poses some interesting questions. Would we give up reproduction for immortality? Is it better to befriend the empire or to resist it? Are messianic figures and "magical thinking" harmful or necessary? He's a well-written, very intelligent (although misguided), almost sympathetic villain, but his space-age philosophizing doesn't represent the entirety of HL2's thematic content. I interpret the work thusly: Gordon represents the player, confined to the scope of the levels, unable to do much more than whack, shoot, and pick up things. The game goes out of its way to make fun of this; in one scene, after Gordon plugs in a cable and throws a switch, Barney comments, "I can see your MIT education really pays for itself." The mysterious G-Man, according to my interpretation, is the video game/designer: all-powerful, governing your actions totally with no option to resist save for outright failure (i.e. dying). Their relationship is an intriguing metaphor for the natural tension between game and gamer, and I can't wait to see how Valve resolves this tale of free will (Freeman, get it?) and the survival of humanity (the species and the spirit) in the face of impossible odds.
Half-Life 2 creates an incredible bond between the game and the player who moves through it. That movement, that process of learning and mastering the mechanics that are so cleverly wrapped in aesthetics and narrative, is special. More than a shooter, Half-Life 2 is a perfect synthesis of science and art. It's a tough act to follow, but I have a lot of faith in Valve. Keep it up.