Valve has ported Half-Life: Alyx to ARM, and it’s free with Steam Frame

Today, Valve is launching its first headset since 2019 — the new Steam Frame — while dodging our questions about whether it’ll ever make another VR game to go with it. But buyers of the $1,059 gadget will get one flagship VR game anyhow, and it’s great.

Every Steam Frame comes with a copy of 2020’s Half-Life: Alyx, one of the best VR games yet made and a good game, period, and you won’t even need a desktop PC — because Valve has ported the entire game to ARM64 so it can run natively on the Frame’s Qualcomm Snapdragon Gen 3 chip.

That’s no mean feat: This was a game that required a VR-ready Windows desktop or laptop with a midrange graphics card back in 2020, now running on what’s effectively souped-up smartphone silicon. It even supports all the mods and extra levels that fans have built! My mods and saves were waiting for me the moment I fired it up.

The port certainly has compromises in graphical fidelity compared to running it on my desktop, but it manages to feel like a full PC VR game on the Frame in a way that native Meta Quest titles never really have, and without removing any objects or assets. Typically, standalone VR games feel emptier.

Valve says (via spokesperson Kaci Aitchison) that’s because the Steam Frame’s built-in eye-tracking cameras unlock foveated rendering — a technique that gives you full resolution where your eyes are actually looking, instead of wasting computing resources on the parts of the image where you’re not:

While we initially didn’t think HL:A running natively on the Steam Frame was likely to be possible, the combination of Foveated Rendering & Eye Tracking turned out to be a silver bullet that enabled us to make it work. The Steam Frame’s 16GB VRAM was also a critical piece, allowing us to avoid having to change any assets, or needing to degrade the gameplay experience.

The company says it took “a year of extra software work within the Vulkan drivers and SteamVR” to make it work, but other developers can now take that work and run with it:

The vast majority of that work was not HL:A specific, so it benefits every other game that runs on Steam Frame. Those bug fixes, optimizations, and extra features were all made easier by the open-source nature of the drivers, allowing our team to iterate quickly without having to wait for a third party.

The Steam Frame doesn’t necessarily need games to be ported, though. Like the Steam Deck and Steam Machine, it can play games that were built for Windows through translation and emulation layers that Valve’s been funding for years, and it can run apps originally designed for Android-based headsets through a layer called Lepton as well.

Rumor has it that Half-Life 3 has been in very active development, though.

Update, September 14th: Digital Foundry has more about the native Alyx port, including that it renders at a base 36fps — though it feels smoother as you turn your head through techniques like reprojection. The headset can refresh at 72Hz or 108Hz for a 2x or 3x multiplier respectively.