Quote Originally Posted by Steam
THE FINAL HOURS OF HALF-LIFE: ALYX is an interactive storybook, written by Geoff Keighley, that takes fans inside Valve Software to chronicle the company’s past decade of game development, including the return of Half-Life.

ABOUT THIS GAME
Twenty-two years ago, Geoff Keighley was in college when he visited Gabe Newell and Valve Software to write The Final Hours of Half-Life. Now, over two decades later, Keighley returns to Valve for The Final Hours of Half-Life: Alyx.

This 25,000 word multimedia experience gives readers an unprecedented and unvarnished look at the past decade inside Valve. From the revelation of surprising canceled projects to never-before-seen images, photos and video, The Final Hours dissects Valve’s creative process and candidly explores the development history of Half-Life: Alyx.

This interactive storybook does not use or require a virtual reality headset. It merges a 25,000 word traditional story with 3D video game technology to give customers a fly-on-the-wall perspective of Valve’s creative process.

FEATURES INCLUDE:

INTERACTIVE “TONER” PUZZLES: Unlock never-before-seen concept art and images via interactive puzzles inspired by Half-Life: Alyx
NEVER-BEFORE-SEEN PROTOTYPES: From early video prototypes of Alyx to other cancelled games, Valve reveals unknown – and unreleased – projects.
HEADCRAB SOUND MIXER: Create your own headcrab sound effects using the same source files as the development team.
DEVELOPMENT FLOOR EXPERIENCE: Explore the Valve office with an interactive 3D tour that showcases the development area for Half-Life: Alyx.
VALVE TIME: An interactive timeline details Valve’s software and hardware projects over the past decade – including previously unknown projects.
RHYS DARBY: Exclusive interview with Rhys Darby (“Russell”), one of the stars of Half-Life: Alyx

Note: The Final Hours of Half-Life: Alyx does not require or utilize a VR headset.
Half-Life: Alyx - Final Hours on Steam
Quote Originally Posted by IGN
Details of Multiple Cancelled Valve Projects Revealed, Including Half-Life 3
Half-Life 3, Left 4 Dead 3, a Dark Souls-inspired RPG, and more.

A new making-of for Half-Life: Alyx has revealed a swathe of games developed and shelved by Valve between the release of Half-Life 2: Episode 2 and Valve's latest VR game. That list includes details on a version of Half-Life 3 that was in development for around a year, and an open world Left 4 Dead 3.
Geoff Keighley's The Final Hours of Half-Life: Alyx is a multimedia making of the latest installment in the Half-Life series - think of it as an interactive storybook - comprising 15 chapters of information about the creation of the game, including videos, mini-games and more.

Within the story, Keighley reveals that at least 5 Half-Life games (not all of which are mentioned specifcially in the text) were cancelled between Episode 2 and Alyx, along with a number of other projects - the most notable being a project officially referred to within Valve as Half-Life 3.

Here's every cancelled Valve project mentioned, and the details provided on them:

- Half-Life 3: Created in the Source 2 engine and drawing some gameplay inspiration from Left 4 Dead, the project known as Half-Life 3 would have used procedural generation between hand-crafted story moments to create a more replayable game. For instance, the game would generate a building and an objective (such as rescuing a prisoner), then create a route through it and fill the building with enemies, meaning that section would always play out differently. The team went as far as scanning Frank Sheldon, the actor whose likeness was used for the series' G-Man. However the Source 2 engine was unfinished, and the project "didn't get very far" before it was dropped. It was in development for around a year between 2013 and 2014.
- Left 4 Dead 3: An open world game set in Morocco and potentially featuring featuring hundreds of zombies at a time, this was also deemed unworkable because of the unfinished Source 2.
- RPG: This RPG project was simply codenamed 'RPG', drawing inspiration from the likes of The Elder Scrolls, Dark Souls and Monster Hunter, and was envisaged as being released in small chunks, but "never really left the conceptual stage". After RPG was abandoned, experiments went into turning it into a single-player RPG based on DOTA character Axe, which were also shelved.
- A.R.T.I.: A light-hearted, voxel-based game that allowed for open-ended destruction and creation in the vein of Minecraft. One version included Half-Life 2 and Portal writer Erik Wolpaw voicing a character called King Kevin, who had to be broken out of prison using the game's tools. A.R.T.I. was later resurrected as a VR game, but was shelved as Half-Life: Alyx grew.
- SimTrek: A VR game develoepd by members of the Kerbal Space Prgram team that was also shelved during Alyx's development.
- Shooter: A Half-Life themed VR shooter that would have been a part of The Lab, Valve's VR showcase. Using only Half-Life 2 assets, it would have had players take part in short gunfights, and was designed more like a Half-Life theme park ride than an continuation of its story. However, it was deemed not to be ready in time for The Lab's release.
- Borealis: A Half-Life VR project, led by writer Marc Laidlaw, that would have been set on the time-travelling ship mentioned in Half-Life 2. Skipping between the Half-Life series' Seven Hour War, and a time period shortly after Half-Life 2: Episode 2, no gameplay details were revealed, aside from that it included a fishing minigame.
- Hot Dog - Another new take on Left 4 Dead, purposely codenamed so that people on the Internet wouldn't know it was a Left 4 Dead game. No details were revealed.
- Vader - Valve's first internal attempt to create a VR headset. Vader was designed without compromise, but was scrapped when it became clear that it was too ambitious. The team estimates it would have cost $5,000 per unit if released. Half-Life: Alyx was initially conceived to launch alongside Vader.

As for what Valve has coming next, Keighley explains that much of the team would like to work on a full-scale, non-VR Half-Life game, but that there is trepidation over the scale of such a project. Encouragingly, however, Valve's Phil Co explains that, after Half-Life: Alyx's release and success, "We're not afraid of Half-Life no more". The Alyx team has previously told us that it wants to make more Half-Life games.

It's also mentioned that a "top secret project" is still in development at Valve, and has been since 2018 - although no hint is given as to what that might be.

The Final Hours of Half-Life: Alyx was released today, and is available through Steam on PC and Mac. There is much, much more to the app than just the cancelled games' information, including insights into Valve's working culture, scrapped elements of Half-Life: Alyx, and story changes that would have wildly changed the Half-Life story. It's a fascinating read(/watch/listen/play) - I recommend you take a look.
Details of Multiple Cancelled Valve Projects Revealed, Including Half-Life 3 - IGN