Update 2: It's official, Half-Life: Alyx is happening. Valve's long-awaited "flagship VR game" will be revealed to the world at 10 am PT/1 pm ET on November 21. The tweet comes from a relatively new account—created June 2019—with a small number of followers, and this is actually its first tweet. It's also odd that Valve would make such a big announcement over a channel that so few people were paying attention to. The official Steam Twitter feed, to compare, has 5.2 million followers.

But it's verified, and the tweet has been retweeted by a few Valve folks, so we're confident it's legit: A new communications channel for a "new" kind of Valve, maybe.

We'll keep you posted.

We’re excited to unveil Half-Life: Alyx, our flagship VR game, this Thursday at 10am Pacific Time.Can’t wait to share it with all of you! pic.twitter.com/BupFCxSrTwNovember 18, 2019

Update: According to a new transcript of the leaked interview, Half-Life: Alyx will be shown at The Game Awards on December 12.

Original story: This November 19 will mark the 21st anniversary of the release of the original Half-Life, and according to rumor it will also be when Valve announce a flagship virtual reality game called Half-Life: Alyx.

Valve are rarely interested in celebrating their own game's anniversaries, so take this rumor with a mouthful of salt. The source is apparently the same leaker responsible for the DOTA Underlords leak, and is quoting from an interview between "Geoff" (Geoff Keighley, in his capacity as the creator of the "Final Hours" documentaries about Valve games), Robin Walker (co-developer of Team Fortress 2 among other games), and an unnamed third person.

"March 2020, "Half-Life: Alyx" comin' out", says Geoff in the transcript.

Responding to the question of whether this game would be available for players without VR headsets, "I mean we would love to be delivering a version of this that you could play with a mouse and a keyboard, but like as we said, it began as an exploration of VR," an unnamed person replies.

As for how this entirely hypothetical game would play, the only clue is this statement: "You can see their whole body-- Respond to the situation. You know, panicking, dropping clips on the ground as they fumble their weapons 'cause a zombie's in front of them, all these things, they're just - it's been really fun watching playtests."

Valve have said they'll be releasing a "flagship VR game" this year.

I've reached out to Valve for comment and will update this story if they reply.