Sounds like you do need to update your Mac. You may also get more help with this if you put it in Game Help rather than Site Help.
As a Mac user myself, I remember having to update and make room for FeralHeart. If you can access your App Store, you should see "Updates" on the top bar; software updates to your computer should help greatly. So maybe uninstall FeralHeart, update your computer, and either download or torrent the Mac version of the game.
If that doesn't work, then could you please elaborate on your problems, please? Your short posts are a little vague on the issues to me, whoops. Sorry if this doesn't help your case.