Why does signing in the Google Play Services not work?

Question

My game cannot sign-in to Google Play Games Services, I do not understand why. I've tried a lot of different solutions, none worked for me, also, I was using Google Guidelines, still, I cannot sign-in (despite I had set my tester account and correct APP_ID).

Manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.hypeofpipe.westernshooter"
    android:versionCode="8"
    android:versionName="0.4preAlpha">
    <uses-sdk android:minSdkVersion="18" android:targetSdkVersion="25" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/GdxTheme" >
    <meta-data android:name="com.google.android.gms.games.APP_ID" android:value="@string/app_id"/>
    <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" />
    <activity
        android:name="com.hypeofpipe.westernshooter.AndroidLauncher"
        android:label="@string/app_name"
        android:screenOrientation="portrait"
        android:configChanges="keyboard|keyboardHidden|orientation|screenSize">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>

</manifest>

Answer 1

Yes Włodek Wolieniuk, I saw in your logcat:

GetToken failed with status code: UNREGISTERED_ON_API_CONSOLE

which led me to this link.

Fact is that when you sign a APK and then ask Google for a OAuth2 token, you have to register your signed app through the dev console.