Which allowBackup attribute is useful to understand if an app can be backup?
I don't know what tool you used for decompiling AndroidManifest.xml but both apktool and Jadx do not show an game_display_name:allowBackup=... entry.
No matter what allowBackup entries you have the only entry that matters is the one in the &lt;application&gt; tag. See Android documentation: https://developer.android.com/guide/topics/manifest/application-element#allowbackup
The other one may be added by the developers because they have not read the documentation carefully.
However the game you are refferring to has a second relevant entry for backup: android:fullBackupContent:

This attribute points to an XML file that contains full backup rules for Auto Backup. These rules determine what files get backed up.

When I look at this XML file I see the following content:
&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
&lt;full-backup-content&gt;
    &lt;exclude domain=&quot;sharedpref&quot; path=&quot;appsflyer-data&quot; /&gt;
&lt;/full-backup-content&gt;

From my understanding of this file format that means that the file(s) in /data/data/com.ironhorsegames.idlewasteland/shared_prefs/appsflyer-data* are excluded from backup.