Hi there,
Sorry to hear about the trouble! This isn't something that I've encountered before, to my recollection, and I'm not sure offhand what it would be. If the game is running into some sort of error, then you could look in the RuntimeData folder that is next to the LastFederation.app executable, in the folder you installed this into. That would likely provide some insight.
If it's a suuuper deep bug, then it could actually have to be found via this log: ~/Library/Logs/Unity/Player.log
What I am partially wondering is if it's loading a bunch of stuff into RAM and having trouble allocating more for some reason. There are many more graphics in the tactical fights compared to the rest of the setup, and loading a bunch of things into RAM might be causing an out of memory exception.
The other possibility is that it's the "Gatekeeper" issue that is mentioned elsewhere (
https://forums.arcengames.com/ai-war-classic-technical-support/mac-freezes-on-load-up-screen/15/). In that case it would likely be the problem is that it's trying to write to the gatekeeper virtual read-only folder to auto-save for you, and thus dying because of that.
The quick fix for that would be to copy the game's install folder to some other location on your hard drive, which I know sounds strange but is really a thing with OSX in the last year. Steam games don't have to deal with this, but anything downloaded directly from the internet is viewed with great suspicion and if you move it into the Applications folder or leave it in the Downloads folder or similar it will freak out.
Hope that something in there helps!
Best,
Chris