- There is an arcade game based off of Half-Life 2, co-developed by Valve and Taito. It's Japan-exclusive as well as the only Half-Life game Japan ever got. No, nothing else from Valve counts.
- Fan Nickname: The Vortigaunt who accompanies you through parts of Episode Two has no official name. Naturally, he was nicknamed Cecil.
- Name's the Same: Adrian Shephard from Opposing Force has nothing to do with that other Shepard.
- Suspiciously Similar Song: 'Space Ocean' from Half-Life 1 was likely sampled at least was the inspiration for 'Fate' from Devil May Cry.
- Shrug of God: Marc Laidlaw is very ambiguous about some parts of the overall continuity. Not only towards the things added on by the Gearbox expansions, but also when it comes to Valve's own games.
The whole issue of canon is something the fans came up with. I guess you will be able to identify as canon those story elements we continue to build on and develop and mention repeatedly as the story progresses. Others might fall by the wayside once they've served their purpose. Couldn't you say the same of us all?
- Trope Namers:
- Vaporware: Common with this series (and even more so for Team Fortress 2, though it did finally get released). Fans have been waiting for Half-Life 2: Episode Three note for so long that it's become a source of videogame-culture running gags, and every bit of Valve-related news will include comments like "But what about Episode Three?" and "Wait: [a convoluted chain of "logic" like a parody of a conspiracy theory]...HALF LIFE 3 CONFIRMED!"
- To put it in numbers: 2 was released in 2004, almost exactly six years after the original in 1998. Episode One had a much quicker turnaround, taking only two years to get a 2006 release. Episode Two came out only a year after, in 2007; this would normally be considered an aversion if the original schedule wasn't "every few months". As of October 2016, Episode Three is still unaccounted for, has been restarted from scratch multiple times, and is nearly ten years and counting since the release of Episode Two, becoming a serious contender to Duke Nukem Forever and its infamously long development span.
- Further frustrating the fanbase is Valve's complete refusal to speak about the game, and rarely acknowledges the franchise even exists beyond off-hand mentions in interviews. Combined with the news of series writer Marc Laidlaw's departure from Valve at the start of 2016, fans are increasingly convinced that Valve has no interest in the series and is letting it quietly die.