Here is a list of items that are tested in your Windows 8 App. If you are in Southern California, please email these posts for more information on getting a token for your app by June 30, 2012!
Windows 8 Metro style design is unique. If you have an application written for a different platform, it might have design traits that might not be consistent with the Windows personality. The Windows personality has specific layouts, font hierarchies, animations, interactions, commanding, common controls, etc. The two most common slipups when bringing assets from a different platform are:
Reusing icons or graphics that have gradients, or 3D, rounded corners, etc. Providing animations that are not authentically digital (such as a page flip animation).
Think about all of these as you design an app for Windows 8. Become familiar with the Windows Animation Library and leverage it to provide transitions that your users will find familiar and intuitive to discover.