Half-Life 2: Episode One

Half-Life 2: Episode One
Cover art showing key character Alyx Vance
Developer(s)Valve
Publisher(s)Valve
Writer(s)
Composer(s)Kelly Bailey
SeriesHalf-Life
EngineSource
Platform(s)
Release
June 1, 2006
  • Microsoft Windows
    • WW: June 1, 2006
  • Xbox 360
    • NA: October 10, 2007
    • EU: October 19, 2007
    • AU: October 25, 2007
  • PlayStation 3
    • NA: December 14, 2007
    • EU: December 14, 2007
    • AU: December 20, 2007
  • Mac OS X
    • WW: May 26, 2010
  • Linux
    • WW: June 26, 2013
  • Nvidia Shield
    • WW: December 15, 2014
Genre(s)First-person shooter
Mode(s)Single-player

Half-Life 2: Episode One is a 2006 first-person shooter game developed and published by Valve for Windows. It continues the story of Half-Life 2 (2004). As the scientist Gordon Freeman, players must escape City 17 with Gordon's companion Alyx Vance. Like previous Half-Life games, Episode One combines shooting, puzzles and storytelling.

After the six-year development of Half-Life 2, Valve switched to episodic development, planning to release games more frequently. They focused on developing the character of Alyx and expanded her artificial intelligence. Episode One uses an updated version of Valve's Source engine, with new lighting and animation technology.

Episode One received mostly positive reviews; the co-operative gameplay with Alyx received particular praise, although the short length was criticized. It was ported to Xbox 360 and PlayStation 3 as part of the 2007 compilation The Orange Box. Episode Two followed in 2007.