Valve licensed out the Half-Life IP only twice in its entire life. First was to Gearbox, who then made the Opposing Force expansion. The second time was to Arkane Studios for what would have been Half-Life 2: Episode 4 - Return to Ravenholm. The game would have taken place in the town of Ravenholm, which you visit briefly in Half-Life 2's sixth chapter, "We Don't Go To Ravenholm...". The reason for that is that it's full of headcrabs and zombies.
The game would have starred Adrian Shephard, the marine from Opposing Force, who wakes up in Ravenholm after having been rescued by Father Grigori. Because of a failed experiment, Grigori accidentally turned all the remaining human survivors of Ravenholm into cannibalistic zombie creatures, forcing the two of you to fight for survival as Grigori works to find a cure.
Related: Half-Life 3’s Cancelled 2015 Build Was The Perfect Sequel
Arkane was working on Return to Ravenholm between 2006 and 2007, but it was canceled alongside Half-Life 2: Episode 3. More than a decade later, we got to see footage of the canceled game courtesy of Noclip, who went to Arkane to play an unreleased prototype. There's even a full hour of gameplay footage online that you can see and imagine what might have been.
Of course, Arkane would go on to find success in Deathloop and Dishonored, but Half-Life fans never got to experience the zombie shooter that it had worked on for a year.
Until now. Thanks to CrunchySoup, we can at least get a taste of what it would have been like to blast zombies to pieces through their Return to Ravenholm SNPCs' mod, currently available for Gary's Mod.
The mod basically recreates Ravenholm's zombies and characters from scratch, icluding Gather Grigori, Adrian Shephard,
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