For example I added menu similar to the one found in windows phone 8 and windows phone 7 where there's an arrow that if tapped will slide to the right to reveal a menu. Note that I used the same arrow that represent the back button in the applications "The one on the top left corner usually."
Implementing this kind of functionality is not a reason to fail - there is a lot of custom menu implementations out there. Just look at Netflix app.
What could make your app fail is that you are using the same arrow. The arrow associated with navigation. If they certification team finds your UI confusing they can choose not to let your app pass through certification.
I would recommend you choosing another icon or symbol. Look at the Segoe UI Symbol font. There's lots of symbols there. To find the symbols in Segoe UI Symbol font use the Character map application included in windows. (Use can use the search charm for this in Windows 8). Select the font: Segoe UI Symbol. Scroll all the way to the bottom and there you have all the icons included in the font.
As an alternative you can look at Sync fusions Metro studio - there's a lot of free icons there you can use too. Link: http://www.syncfusion.com/downloads/metrostudio