Half Life, made by Valve using an improved quake 1 engine, was released in 1998 and it is one of THE BEST video games ever.
Although this was the first game made by Valve it was a huge success due to it's intense gameplay that gives an unique experience. The Half Life world is seen through Gordon Freeman's eyes, a mysterious 28 years old scientist working at the restricted base Black Mesa. Gordon never talks and the entire game is in first person camera so you really feel like YOU are at Black Mesa not him. Half Life was the first video game that used scripts which makes the game feel alive! Really good AI behaviour, the lack of cut-scenes and the permanent first person camera turns the game into a simulator where you are in the middle of hell, on your own so you have to fight in order to survive!
Because of a strange malfunction during an experiment a portal to another planet is opened and Terra is invaded by aliens. A special military force receives orders to kill all the scientists from the Black Mesa facility. You play as Gordon Freeman who is in the middle of cold-blooded aliens and the army so he has to fight them both in order to survive. The nemesis of the game is Gman, a mysterious agent with a strange briefcase, who has the ability to travel through space and time. Gman can be seen several times during the game and he always gets you in trouble and then strangely disappears. After defeating the alien leader you find out that this was only a test by Gman who wanted to see if you are ready to complete a special task. The game lets you decide if you join Gman or die.
Originally the game was supposed to be released in 1997 but Valve decided to remake the whole game transforming a very good video game into a masterpiece! The game graphics were fantastic when the game was released and it created realistic environments. Every part of the environment had a logic and nothing was random. For example ammo could be found only near dead corpses (like security guards, soldiers etc) or in special places (a storage for example) not random placed like other fps.
Half Life's gameplay was realistic in 1998 and it blended well with the unique enviroments and the game scripts. The limited abillities, ammo and health made you feel like a human and not a video game character. Human npc's die from a few bullets and they can be slowed down if you aim their legs. Some alien NPC's can be distracted with food giving you the ability to sneak past your enemies instead of brainlessly kill them. Also Half Life was one of the first games that introduced the reloading system in the gaming industry influencing the modern fps!
Because of the unique game "cut-scenes", the use of scripts and a really good AI Half Life is not a video game but a simulator that lets you experience moments from Gordon Freeman's life!