August Update
Posted 13 days ago
You can now export your game to be standalone. It's not perfect and you can't distribute your exported games, this is a tech demo, so we can show Valve how it's going to work in an attempt to get their permission.

Here's a clip of me exporting our testbed game, and then running it - no cuts, no speedups. You'll notice that launching the game for the first time is a bit slow, we're aware of that, it's something we'll fix.