It has five games on it - Half-Life 2 , Half-Life 2 : Episode One ( an expansion of Half-Life 2 ) , Half-Life 2 : Episode Two ( another expansion of Half-Life 2 , Portal , and Team Fortress 2 . Two of the games included , Half-Life 2 and its first stand-alone expansion , Episode One , had previously been released as separate products . Three new games were also included in the compilation : the second stand-alone expansion , Half-Life 2 : Episode Two , the puzzle game Portal , and Team Fortress 2 , the multiplayer game sequel to the Quake modification , Team Fortress .