Many argue that the original Half-Life represented a significant step forward for the first-person shooter genre in the late '90s. Developer Valve won further acclaim with Half-Life 2, which introduced substantial gameplay refinements, a cast of relatable characters, and, of course, the almighty gravity gun.
Eric Rosloff: "As a PC gamer, the answer is obvious: Half-Life 2. Along with raising the bar in graphics, physics, and gameplay, it spawned the source engine which is still being used to make great games today. It also launched the Steam distribution platform, which is quickly becoming a dominant force in the PC gaming world."
Tyler Lovemark, Art Institute of Portland: "Improving on the original Half-Life was a challenge in and of itself. A sequel to the game that jumpstarted the PC modding community and revitalized the PC shooter genre had an enormous amount of hype and respect to live up to.
"Half-Life 2 succeeded in not only introducing a new physics-based engine which still influences today with encouraging players to manipulate their environments, but also in being a highly refined game with a tight narrative and inspired setting."
John Painter: "Probably the first pure FPS to actually make you even vaguely care about the secondary characters it presents, with excellent level design, pioneering graphical flair and the story power to keep people caring about the third episode more than 5 years after the original was released on the same engine.
"Half-Life 2 has entertained the masses, inspired copycats and essentially put itself at the head of the most crowded genre of the day both then and now. It's pretty much the only game I can think of being worthy of the title of 'Game of the Decade'."
Garth DeAngelis, Firaxis Games: "Immersion, storytelling and atmosphere without ever taking control from the player."
Anonymous: "It had a revolutionary mechanic that it did not lean on. Even without the grav gun, Half-Life 2 would have been the best first person shooter ever. It is rare that a game so deftly combines innovation and execution."
Mark Newheiser: "Every Source game from Portal to Left 4 Dead owes a debt to it, it showed you could tell an immersive story without taking control and initiative away from the player, and through the transformative power of physics it turned every object in the game into a viable weapon.
"It set a new bar for the technical accomplishments of its engine, the depth and variety of its gameplay, and its uninterrupted flow of storytelling. I'm proud to speak up for Gordon Freeman, since he apparently can't speak for himself."
Randall Theil: "No original universe has compelled and interested me to the same degree and no other single player progression has been as polished and seamless. In many story driven games, especially in the sci-fi genre, the setting is the focal point of the story and the characters become just window dressing.
"Half Life 2 did a very smart thing by only revealing details about the world pertinent to Gordon Freeman's experience, and by driving the action forward with some of the best character design in any action game. The voice acting is top notch and the script is excellent and brief.
"Half Life 2 had great action too, of course. The game mechanics and level design are constantly changing. At each turn new weapons and tools are added to Gordon's arsenal, and each environment is distinct in design and theme, from the dark, claustrophobic alleyways of Ravenholm to the bright, airy openness of the coast.
"Like the story, the quality of game play of Half Life 2 reflects the constant iteration Valve puts into the design process. At about twelve hours to play through, Half Life 2 was big for an action game, but it never felt sprawling.
"Unlike Mass Effect, I never felt overwhelmed by the amount of lore that Half Life 2 offered me. I ate up every detail of the universe that they offered me because they only put the best of what they had on display. Unlike Halo, the game play never became tedious for me because exploration was as much a part of the game as shooting was, and the levels were worth exploring. Half Life 2 was a concise, compelling, controlled experience. The cream of the crop of the decade."
Mitja Roskaric, ZootFly: "* It revolutionized the FPS genre. * Good story. * Telling the story without taking control from the player. * Great level design !!! * Gravity gun. * Good pacing (mix of combat and puzzles). * Lots of well design set-pieces. * Varied combat ( combine & xen ). * Good AI * Well designed driving sequences. * Memorable characters."
Luke Stillman: "While there were many fun or impressive games over the past ten years, Half-Life 2 was the only one to truly introduce a new gaming element: physics. Sure, there were physics of a sort in all prior games such as Mario's jumping physics or even Tresspasser's misguided debacle of an attempt at a full physics engine. HL2 was the first game to really make the leap into believability and its foray was so impressive that it is yet to be topped.
"Crysis might have its barrel demonstrations, but HL2's tech demo had a massive Pachinko machine years before. Physics and physics-based gameplay mechanics are really the innovation of the past decade and the only gameplay element that did not exist in the 1990's, and for that reason it is without peer.
"On a more personal note, it mattered because it was the impossible sequel to one of the greatest games of all time. You've seen from the recent Modern Warfare 2 that it's a difficult task to live up to a groundbreaking title. Half-Life was for many the titleholder for 'best game,' so it is no casual comment to say that aside from the online deathmatch, HL2 surpassed its predecessor in every way.
"I know that many gamers (including myself) shared a moment of elation when that first crowbar advertisement was released in 2003 whose shadow formed the number 2. No other details were needed: Half-Life 2 was coming. We all knew it would be fantastic, and it was."