ok fixed, just open terminal and then run the following command:
sudo chmod +x "[pathname of doodle empires]/Contents/MacOS/Doodle Empires"
so for example, for me, the command was:
sudo chmod +x "/Applications/Doodle Empires Mac.app/Contents/MacOS/Doodle Empires"
then run it, but run it by right-clicking and then pressing "open" from the dropdown menu instead of just double-clicking like usual.