Half-Life: Alyx now runs standalone on Steam Frame, with every original asset left untouched

Half-Life: Alyx now runs standalone on Steam Frame, and Valve got it there without changing a single asset. Valve's September 14 patch notes say the update "ported the game to ARM64/aarch64" and updated "most of the engine without altering any of the content".

Steam Frame includes a redeemable copy of Half-Life: Alyx, one per headset. Image: Valve

The same update adds two tricks that only apply on the headset. Foveated rendering is supported "when running standalone on Steam Frame", and depth reprojection allows "smooth gameplay at lower framerates".

That makes it a native ARM build rather than an Android APK, and it is the game Valve bundles with the Frame. Six years after launch, Valve's flagship VR game is being asked to run on a Snapdragon 8 Gen 3 rather than a gaming PC.

Valve kept the content untouched on purpose

Valve explained the approach in an email interview with Automaton published on September 15. "Surprisingly, the in-game assets are unchanged," Valve told the Japanese outlet, adding that the team "didn't originally think bringing Alyx to a standalone system would be possible".

What changed its mind, according to Valve, were "early foveated rendering and eye tracking experiments (along with 16 GB of RAM)". Steam Frame has eye tracking and 16GB of LPDDR5X memory in both models.

Leaving the content alone has a practical upside for the game's modding scene. "No content changes allows all the workshop content to just work," Valve says, and it calls the result "the best version of Alyx we've shipped yet."

Valve also frames the port as groundwork for the rest of the library. The work "led to numerous improvements in our graphics drivers, new features to Vulkan, and new options for depth reprojection," it told Automaton.

Automaton's interviewer adds in a note that Alyx was the only VR game he found running natively on the headset, while most of the others that ran well were APK ports from Meta Quest. Valve's patch notes give no frame rate or resolution for the standalone version.

PC players get the patch as well

The update is not only for Frame owners. Its general fixes list "additional performance improvements when running on desktop PCs" and remove "1 tick of latency on player hands and other simulated objects", which applies wherever the game runs.

Linux players get working cross-platform cloud saves and subtitles that actually appear. Valve also fixed a false low-memory warning on some GPU configurations and a main menu that flickered for some users.

A second patch followed on September 17. Valve's notes for that update say it fixed issues where "some users could not launch the game or the workshop tools", along with validation errors when launching on Linux through Proton and stability issues "on all platforms".

The headset's own software is being tuned around the game too. SteamOS 0.3.0 for Steam Frame, released on September 17, lists "Improved motion smoothing behavior in Alyx" among its changes.

One free copy per headset, and none for existing owners

Steam Frame comes with Half-Life: Alyx, as Valve's launch post confirms, which settles the rumour of a bundled copy from earlier this month. The headset costs $1,059 in the US, and Valve's FAQ says buyers are prompted to redeem the game in Settings when they log in on the headset.

The catch is for everyone who bought Alyx for their Index, Quest or Vive. The launch post says that if you already have it in your library, "you will not be able to redeem another copy", and only one copy can be redeemed per device. Valve mentions nothing in its place.

Existing owners lose little in practice, since the Steam Frame build arrived as an update to the same Steam app.

Back when a fan ported a single scene of Half-Life: Alyx to Quest 3, a full standalone version looked like a stretch. Valve's answer was its own headset, first reported as a possible free bundle on September 1, and a game that ships to it unchanged.