Half-Life 2: Episode One is a FPS, Action, Sci-fi PC game, developed by , available on Steam and published by .
Half-Life 2 has sold over 4 million copies worldwide, and earned over 35 Game of the Year Awards. Episode One is the first in a series of games that reveal the aftermath of Half-Life 2 and launch a journey beyond City 17. Also features two multiplayer games. Half-Life 2 not required.