Is there a way to delete or reset the achievements you have unlocked with the google play games app?
I think it would defeat the purpose of the system if people could manipulate it like that. I dont know of any game networks with achievement systems like this that allow you to delete progress. You may be able to delete the record if you have never unclocked an achievement before but there is no way to reset progress so you can start again or anything like that. You will just have to create a new account.