I have a problem with implementing the Google play sign-in as show in your blog here
I have followed the instructions, and the problem lies at the google part of the authentication.
More particular at the line with code at the example:
Social.localUser.Authenticate((success) => {
success is false.
Moreover, I have a remark regarding the tutorial, you mention in the "prerequisites" step 3:
It is preferred that you already have a game created in the play.google.com/apps/publish dashboard (although it is not a requirement).
My remark regarding this step is that having a (Draft) project (Draft because we are currently in development) at play.google.com/apps/publish dashboard, does not mean that there will be a project in Google developer console, as I understand that you mean in "Setup for google" step 2.
You have to create a game service in google game services in order to already have a project there. Thus creating a project is still necessary if you do not have game services. This goes both ways i.e. creating a project in Google developer console does not mean that a project will automatically appear in play.google.com/apps/publish.
Is creating a google play services project and configuring that Project in "Setup for Google" a requirement to make it work?