Is there a way, from within the Amazon App Store Developer Console perhaps, to clear all achievements for all users for a particular game? We have very thorough testers who want to make certain the achievement system in our game works correctly, and then to regress those tests. The problem is that the achievements appear to be a set once kind of deal. Thank you!
That feature has not yet been implemented in the Distribution Portal. If you require achievements to be cleared, please send a request through the Contact form:
https://developer.amazon.com/help/contactus.html, and one of the support staff can help you out.