The game seems to have problems running on the 2015 MacBook Pros. I'm not exactly sure what the cause is but you can try downloading it with another browser or updating your OS (but you are updated to Mojave so this is for all the other people with this problem).
If you haven't yet, you can also try typing this in your terminal:
sudo spctl --master-disable
What this does is allows apps downloaded from anywhere, as this option was removed from the security and privacy settings a while back.
Hope this helps!