They may be hosting the files for Batman: Arkham Underworld (now discontinued) or the mobile version of Batman: Arkham City Lockdown . These are not the full console experience.
Since you are installing an app from outside the Google Play Store, you must allow your device to do so. They may be hosting the files for Batman:
If you own the game on a physical console or PC, you can stream it across your home network to your Android device for free. If you own the game on a physical
Most fake APK files are Trojan horses designed to steal personal data, track your keystrokes, or access your banking apps. track your keystrokes
If you encounter a file named "39link" or a download button that says so, you should treat it as a potential risk, as it might be a mislabeled file or a link to unsafe software.