.NET library has not been updated recently, so I don't think it has the Drive APIs in it. Do you see any library that actually has Drive code in it?

You're right, these are just the generic Google API libraries.

There is a sample .NET app for GDrive: https://developers.google.com/drive/examples/dotnet

That's still not right - in step 5 it asks to register Chrome something or another. So it's only to write web apps, not native apps.

It looks like the Chrome Web Store is the centralized place for developers to list apps and for users to authorize them. But once the app is registered/authorized, I'm not sure how the server would have any idea whether requests were coming from a web app or a desktop app.

If this is the case, then a native app could exist Chrome Web Store solely for the purpose of letting users authorize the app to access their GDrive.