Clear your device cache and clean your storage if you are close to full that could show the process. Another idea is if your using your phone go try it at another wifi location and see if it makes a difference
No luck. I am using a desktop PC (Debian Linux OS, not Windows), so "try another location" is not a direct option... Although I can change the phone's location around my house/yard when I use it as a WiFi "hotspot".
Also, I just finished a 4.4GB DVD image (unrelated to this game) download in under an hour. I tried again for this; Mega is still showing me >12 hours and Google Drive showing >8 hours. Google surprises me the most, because I usually have very high transfer rates when using it.
The reality is, the dev had to switch to hosting it elsewhere for a reason. That should have been the very first sign that something else needed to be done to address the issue.
But at this point, I am not going to try any harder.