After Ars spent Half-Life 2's 20th anniversary week looking back at the game's history and impact, Valve marked the occasion with a meaty two-hour YouTube documentary featuring insider memories from the team behind the game itself. Near the end of that documentary, longtime Valve watchers also get a chance to see footage of the long-promised but never-delivered Half-Life 2: Episode 3 and hear more about what led the project to be abandoned. The Episode 3 footage included in the documentary focuses heavily on a new ice gun that would have served as the episode's main new feature.