Well it was a little expected - basically the flagship game for VR

A lot of people still haven’t played it. I can’t even afford a Steamdeck much less a VR headset.

How many current VR games (or Linux games in general) have arm builds?

There should be a ton of current VR games that have ARM builds because the Meta Quest is also an ARM-powered device. But I believe that it runs some customized Android, not Linux, so that part might be trickier. Still, I also understand that Steam has included a compatibility tool to allow running Android games on it. Between those two things, there should be plenty of games that could be converted to run natively on Frame without too much effort, I would think.

Do you mean the Source 2 engine? I don't believe Valve has released it for third-party developers to use, even though Valve released the first game with it 11 years ago.

Gunman Contracts started out as a HL:A mod, it just released.

Boneworks had a homemade engine called Marrow I think, so I assume Bonelab is too? I just looked it up:

The 1Marrow Interaction Engine (or just the Marrow Engine), is a proprietary physics framework developed by Stress Level Zero for the Unity engine. Originating from BONEWORKS' mechanics, it contains all physics, solvers and logic used to create physics-based VR games such as BONELAB.

Bonelabs is made in unity and is based on boneworks

Because source

I didn't understand this so I looked it up. The game literally can run on the headset's mobile chipset, no computer needed. Possible through foveated rendering. Absolutely insane. And there are 131 verified titles at launch.

I agree. It's been my prediction that Valve will use this to publish mobile games. They already have the Steam app. There's also an app that already uses this that lets you play your Steam library on mobile (GameNative). I think Valve would be stupid to not push a patch to the Steam app that allows you to play your games on mobile.