Half life 2 was released on November 16, 2004 and is the sequel to 1998's Half life. Half life 2 was developed and published by Valve Corporation.
"Like its predecessor, Half-Life 2 is a single-player first-person shooter broken into several chapters, permanently casting the player as protagonist Gordon Freeman. The sequel has similar mechanics to Half-Life, including health-and-weapon systems and periodic physics puzzles, except with the newer Source engine and improved graphics. The player also starts without items, slowly building up their arsenal over the course of the game. Despite the game's mainly linear nature, much effort was put into making exploration rewarding and interesting; many optional areas can be missed or avoided." - Wikipedia article on Half life 2