Open terminal. Type in "sudo chmod -R 755 " then the .app pathway (right click game and click "copy "MAC"". Open the .app again. This works for tons of games when that happens so keep it handy :)
So it seems a lot has changed with the downloaded version (I honestly just recommend you use the browser version) but I got it working. After you download the Mac version of the game and unpack it with whatever app you’re using (I use unarchiver) you’ll get a folder named “MtE v3.11 MAC”. Open that up, right click the third item and hit “show packaged contents”, you’re gonna go into the contents folder, go into the MacOS folder and you’re gonna see a file named “MAC” right click that and click on “copy “MAC””. Open up Terminal (this can be hard to find if it’s your first time using it) type “chmod a+x” and paste what you copied. Then go back and try opening the “MtE v3.11 MAC” file, it may have a pop up that says something along the lines of “unidentified author” hit cancel and then just right click MtE v3.11 MAC and hit “open” that pop up is gonna come up again but you should now have a new open option, click that and the game should start loading👍