Simply, perfect.
Why? Because Half-Life did more for its genre, dynamic gaming and just gaming in general than any and all of those aforementioned games COMBINED. This is truly the only game worth considering for the title of "Greatest Game of All Time", regardless of how partisan or steeped in PC-hate you are!
Graphics: 10/10
At it's time Half-Life was a marvel of graphical power. It was the best looking game on all platforms and among all future releases that one knew of at the end of 1998.
From it's vast, expansive levels dripping with detail to it's amazing monster designs, animations and special effects Half-Life had it all as far as graphics were concerned. How many people can forget the memorable introduction sequence with its ensemble display of the whole Black Mesa compound, the myriad of things happening at any one time in the compound, the robots carrying crates from left to right or the glowing pools of acid?
Character design faired just as well in Half-Life, with fully lip-synched characters ranging from the most minor to the most important of them. Needless to say, they all animate like a high quality Disney production. Framerate, resolution and technical excellence were all part of the Half-Life package and were done in such a way that they would actually WORK on the minimum system requirements. Just try to remember what was the last game that did that and, maybe then, you'll understand what Half-Life's graphics were like.
Sound: 10/10
Dynamic sound - in Half-Life, when the music plays at key moments of the game to speed up the action, get the blood pumping and increase the "feeling" 10-fold.
This was what Half-Life gave gamers in terms of sound: Music in games that doesn’t play throughout the level but only at key points to indicate the urgency of the situation. It would honestly take me 2 pages to just list all the games that used this technique, but among the more famous we can observe Halo and Doom 3. What’s more, the music in Half-Life was so well composed and was so proper for the action on screen that I honestly keep wondering where the guys at Valve came up with it.
The sound effects packed an equally satisfying punch. From the echoes of footsteps on metal floors, to the hungry gasping of the Devourer as it's pulling the player up towards it's mouth to take a good chuck out of his or her head off, to the scrambling of the marines and the repeated radio chatter like "He's here!", "Look for cover." and "****", Half-Life not only did it all with style and enough professionalism to rival any Hollywood production but it was also one of the first games to feature full 3D sound-support. Needless to say how many followed suit, yet again!
Gameplay: 10/10
In order for me to list all the improvements that Half-Life brought to games and how greatly it influenced or refined gaming through it's gameplay I'd need the equivalent of a 10-page precis. So I'm gonna stick to the basics with this one: There has been no OTHER game ever(!!!) to feature so many revolutionary techniques within the course of its game time.
Let's start with the story. For the uninitiated, Half-Life was the first real FPS to feature a real story and *gasp* plot twists and characters that you DIDN'T have to shoot if you didn't want to! The story in Half-Life goes something like this: You are a scientist employed by a mega-corporation called Black Mesa. It deals with experiments on interstellar communication and teleportation. One day things go terribly wrong and one of the experiments opens a rift to an alien world which causes a massive alien invasion of the laboratory/base. From here on, your purpose is to try to help your fellow scientists and survive the alien onslaught... however, things get worse when you find out that the government believes the words "help" and "exterminate all living souls" to be synonymous.
I can't even begin to tell you what this meant for FPS games in 1998. First off, you weren't saving the world, second you actually had a character with a NAME and a real LIFE, third you were faced with situations that had never before been seen in an FPS, fourth- you see where this is going! The story in Half-Life was every conspiracy theorist’s wet dream and the fact that it's basic core elements (evil alien race, 3rd party appears later on) have been repeated in countless FPS games since it shows what an impact it had on the gaming world.
The characters that appeared in Half-Life were fairly varied and despite the fact that they weren't the most fleshed personages you've ever seen in a game they made Half-Life feel so much more alive than the other hundreds of Doom or Quake clones out on the market in 1998. For example, even your HEV suit became a character in Half-Life as it had an awesome way of warning you of injuries suffered or of telling you that the green goop in front of your feet isn't Laffy Taffy but actually, highly corrosive acid. There were also moronic scientists and hopeless police guards and they all did what they could to hide from the disaster or escape. One character however was always there, always observant never fearing the consequences and always untouchable by Gordon: The mysterious G-man. The G-man became synonymous to "government clean-up man" as soon as the game came to its satisfying end and pretty much gave birth to an Internet frenzy, as well as one of the most popular characters ever in a PC game.
But grasu, some of you might angrily direct at me, Strife had a story and characters that you WEREN'T suppose to kill. What the hell makes it a less revolutionary game than Half-Life? Well, dear reader, that's simple: Strife had gameplay that was equivalent to that thing you just stepped into while Half-Life had a great story and great gameplay in one little package. And gameplay we shall discuss! P.S. Not to mention that in Strife you had no choice if you wanted to kill the characters or not since if you tried, you’d get butchered.
Let's make some things clear before we start discussing gameplay: If you weren't around when Half-Life was released or your best example of an FPS is Goldeneye you won't EVER even begin to understand what Half-Life did for gamers. In 1998 things in the FPS market were stale and boring, we had hundreds of testosterone infused killing machines mutilating each other with BFGs and rocket launchers in the world of PCs. Things were boring, repetitive and totally over done. No one ever killed Quake 2 despite the fact that there were so many games that had "The TRUE Quake-killer on the box" that it made you sick. Then came Half-Life and Quake became garbage.
Half-Life's gameplay revolves around a concept that was unheard of in games at that time: Freedom. You had multiple ways of tackling the same problem. You could go back and forth between sections of the same level, and there was NO level to being with. It was all one big adventure strung together by (very) short and negligible load times. These "sections" of what can be best described as a huge jigsaw puzzle ranged so greatly in theme and size that the first time I played this game I was moving on only to see what other insane level had the guys at Valve thought of next. In addition to the amazing level design, the variety of scenery and the freedom Half-Life gave you, it was the first game to truly use "scripting" in FPSes to great effect. Unlike in Quake 2, where scripting was just another way for the game to fill a room with bad guys and force you to terminate them all in order to move on, scripting in Half-Life sometimes actually KILLED you if you weren't thinking on your feet. Dams got blown up, bridges fell, earthquakes shook the foundations of buildings, and you had to run, kill and interact with characters in this myriad of exhilarating circumstances. And despite the slightly more lackluster feel of the Xen-world levels even they weren't as boring as 90% of the levels in Halo or most FPSes that come out now-a-days... and yes, I'm counting Half-Life 2 as well.
Really though, it was the shooting game that made Half-Life into the gaming giant it is now. The pace of this game was so frantic and so exhilarating, while your opponents so sharp and perceptive that even the beginning sections of the game when you were forced to conserve ammunition and had just a mere crowbar made for some of the most chaotic and unforgettable moments in gaming history. Endless firefights with monsters that were either so strong that they took whole minutes to take down or constant covering or retreating behind walls or barricades to refill shields were never part of Half-Life. The well balanced weapons made every fight count and every bullet could carry death with it, just like in real life. This combined with the great pace of the levels themselves which had you running or gunning made Half-Life’s pace unbeatable in 1998 and unmatched in 2005!
Suffice to say that the weapons in this game put most other FPSes to shame. Even now-a-days the rocket launcher is considered to be the best weapon in some 90% of FPSes when, in 1998, Half-Life was pissing this concept away. Weapons ranged from guns, to crowbars, to crossbows, to laser guns, and, yes, even rocket launchers. Nothing was, however, overpowered in Half-Life. Nothing had TOO much ammo. Everything need to be reloaded! Oh and did I mention "secondary fire"? Yeah you could now fire weapons in TWO ways, sometime either forcing you to take a longer time to charge up for each shot, while sometimes giving you a faster firing rate at the expense of fire power. Match that for innovation Halo!
Another often forgotten aspect of Half-Life is the system of pickups that it used and the ways in which you recharged your health and armor. For the most part, gone were the medpacks and battery packs (as these were only seldom found) and a new system called HEV stations that refilled your suit's power or your health was used in place. Half-Life also had a myriad of puzzles, including everything from button mashing, to orchestrating aerial attacks in order to defeat stronger foes. These puzzles, even if some weren’t so successful (like some of the jumping puzzles) made Half-Life stand out as not just a simple run-and-gun shooter but a game that took some brains to beat. Hell, even the idea of a “flashlight” was introduced by Half-Life! And, yes, that was revolutionary at it’s time!
The enemies Gordon fought in Half-Life were unique, to say the least. The fusion of worldly foes such as marines with alien foes such as the dreaded headcrabs or the devourers was, and for that matter still is, a defining trait of Half-Life games. I remember that when this game came out people were actually wondering how they were supposed to kill the first headcrabs they bumped into (since they had no weapons). That is innovation. That is what Half-Life is about, and the AI is equally as intelligent and capable of handling the situations it faces just like any regular human. For the first time in an FPS we saw enemies that ran for cover, that regrouped or that actually outmaneuvered US! Long gone were the days of Quake when everyone came charging towards you in a zigzag pattern, guns-a-blazing and just waiting to be taken out by a massive BFG charge. Now there were enemies you COULDN'T kill with your own weapons, you had to evade them, trick them or find cover until they passed. One classic Half-Life moment had the player facing 3 huge claw-like-things that reacted to sound. Your job was to go down a few ladders, across a metal railing that reacted to EVERY footstep WHILE avoiding the claw-creatures’ attacks. Frankly, I've never seen this duplicated in any other FPS since Half-Life and I've played all of the memorable ones in the last 10 years.
All of that being said, I probably left out many other innovations that Half-Life brought to the genre and to gaming. In order for me to find out about all the innovations however I'd have to play this game at least 3-4 more times while paying great attention to detail as Half-Life strings everything so seamlessly together that it's hard to even pick out what this game does best for gamers. Furthermore, Half-Life had no real bugs or game wrecking unbalances which made single player, as well as multiplayer a blast and, suffice to say that through the 15 or 20 hours that this game might take an average gamer to complete, he or she'll have more orgasms than during all of the sexual escapades in his or her life!
Multiplayer: 10/10
Out of the orgasm-induced coma yet? Good, brace yourself, multiplayer Half-Life is probably even better than the game itself. Hey!? What the... get the hell off the floor!!
Half-Life's multiplayer is easily the most oft-ignored part of this godly piece of gaming. Half-Life's multiplayer is not Counter-Strike! It's a sleek brand of shooting, strategy, amazing level design, balanced weapons and a whole slew of innovations that put most of the so called "great games" from other platforms and the PC to shame.
Where can one start with the multiplayer in this game? First off, let's talk players: Half-Life supported 32 players at one time. That's all you have to know in terms of technical innovation as not other game before it even ATTEMPTED to accomplish this feat, the only one that even got close was Tribes and even it was way off the target. 32-players and seamless Gamespy integration meant one thing: A need for great multiplayer battlefields on which players could kill each other in peace. (You should already know where this is going by now...) Half-Life had multiplayer levels that, to this day, are some of the best in the industry.
Half-Life’s multiplayer levels ranged from small, one chamber death arenas populated with several bunkers some kick ass weapons, and a lot of ammunition to true BATTLEFIELDS in the vein of the two Compound maps, which feature nuclear bomb installations that can wipe out everyone who can’t find hiding inside a windowless building or a nuclear bunker. Other maps that might spring up some good memories are Office, an office battleground with computers, staircases and all the works for a great multiplayer match. Or the many other maps which involved everything from huge underwater fights to big-time all out war that I've long forgotten by name.
Of course this all would be for naught if Half-Life's single player weapons would be unbalanced or if the game would simply not be fun but, this is not the case. The fun I had with this game in LANs just simply cannot be compared to anything before or after it and I've been gaming for a longer period of time than most of the people on this site have been on EARTH! How's this for a typical Half-Life match? You blow someone up with the rocket launcher just to start frantically running 10 seconds later because while you were reloading your RPG, a crowbar-psycho assaulted you; finally, you manage to find a shotgun and you blast the moron to smithereens, now you're on your way to a HEV station to refill your health (INNOVATION NOTE: Half-Life was the first game that didn't feature health packs during multiplayer matches) and to get some armor just to find out that both of the stations are empty. Wounded and with 3 bullets in your shotgun you prepare to face the battle going on downstairs, where 20 players are killing each other mercilessly and a guy called "ipwnu" is pissing on everyone from a distance. Just another day, and just another amazing game of Half-Life.
Strategy also became an integral part of the Half-Life experience only a few days after the game was released as people argued if long range weapons like the pistol were better for starters than the more powerful crowbar or if the laser-guided missile of the RPG was more of an actual recipe for defeat than it should be. The player had to take these decision in split seconds on the battlefield and apply them as he or she saw fit and this, along with everything else, made Half-Life's “vanilla” multiplayer much better than most people care to know about.
Overall: 10/10
As you can clearly see, I love this game. Half-Life will forever take a soft spot in my heart as the best game of all time and some of the most fun moments of my life as I fragged with buddies in damp, dark and sweaty internet cafes for hours without much care for money or time wasted.
Half-Life was, and will be, a part of PC gaming history that won't ever come to pass again. It was a time when the PC was king and when games could truly innovate so much that they could truly change the face of gaming. Gamers enjoy this game; for another is never gonna appear.