All games in the 'Half-Life' saga are free on Steam as an appetizer before the release of 'Half-Life: Alyx'

These are the games that the promotion includes (unfortunately the mentioned 'Portal' games, which are and at the same time are not 'Half-Life' spin-offs, are not included)

• Half-Life
• Half-Life: Blue Shift
• Half-Life: Opposing Force
• Half-Life: Source
• Half-Life 2
• Half-Life 2: Episode One
• Half-Life 2: Episode Two