It’s hard to even comprehend how much PC gaming has changed in the past 20 years. But it was the classic FPS Half-Life 2 that convinced people to install this weird military-green launcher app named Steam and take the plunge on digital distribution. Not only was it a fantastic game, it built on Valve’s established track record of mod support, providing creators with the tools to create their own levels, campaigns and total conversions, even if the studio's own plans could be a bit of an inscrutable black box... Read more.