This may help
Well, that certainly answered my question. Since I was planning to export my game using Scirra's Construct 2 HTML5 engine, I don't know if my app can meet the user interface guidelines. It's an HTML5 app, and Scirra has made an exporter for Windows 8. But I don't think it will even come close to very strict guidelines that your link linked to.
I understand that you want the early apps in the app store to be outstanding and you've learned your lesson from the Windows 7 Phone apps, but I feel the standards are way too high.
Ashley, does the Construct 2 export for Windows 8 follow these guidelines?
UX Guidelines for Metro Style Apps
These are HTML5 games, not applications! If one looks in the Apple app store, a very large percentage of the store are games! I can understand UI guidelines for apps, but not games. Run it, play it, have fun.
In case you're curious, here's an early version of the game I'd like to put in the app store. It works in Windows 8 just fine. Visual Studio can compile it. It doesn't contain anything offensive. Tilt-A-Twirl I've already put it in Chrome app store and it is going in the Mozilla store next week.