Taking place in and around the fictional City 17 in 2020, Half-Life 2 follows the scientist Gordon Freeman. Dr. Freeman is thrust into a strange environment in which the aftermath of the Black Mesa Incident has come to bear fully upon human society. Freeman is forced to fight against increasingly unfavorable odds in order to survive. In his struggle, he is joined by various allies, including fellow Black Mesa colleagues, oppressed citizens of City 17, and the Vortigaunts.
The game uses the Source game engine, which includes a heavily modified version of the Havok physics engine. Half-Life 2 has been critically acclaimed for advances in computer animation, sound, narration,
computer graphics, artificial intelligence (AI) and physics. At the start of the game, the G-Man speaks to Gordon Freeman as part of a hallucination-like vision as he is pulled out of stasis. The world has been overtaken by the Combine forces. Gordon meets up with Barney Calhoun and sets out for Doctor Isaac Kleiner's lab while being chased by Civil Protection.
Gordon eventually meets Alyx Vance and is taken to Doctor Kleiner's lab. Here, an attempt to teleport Alyx to Black Mesa East works, but the teleporter fails for Gordon due to interference by Kleiner's pet head crab Lamar and alerts the Combine of Gordon's arrival in City 17. Barney instructs Gordon to take the city's canals to get to the lab of Alyx's father, Dr. Eli Vance.
Codes
Cheat Codes Anytime during gameplay enter:
Up-Up-Down-Down-Left-Right-Left-Right-B-A - Restores 25 pts of health each time it is used.
Y B A X White Y X A B White - Restores ammo for current weapon
Left x4, Black, Right x4, White - Unlocks all chapters
Here's some neat gameplay footage from the Xbox version of the blockbuster title Half-Life 2: