I will still say that with Free Pascal and/or Lazarus you have next to the best portability for your code though.

And even if you can't figure out how to rig your game for the App Stores on Mac, there is still gamer communities like Steam where I'm sure publishing doesn't require Apple's more strict validation process. You can also release the game under both Mac and Windows in parallel there too which would be easier to manage having only one distribution system to deal with.