No, so long as you are writing to your app’s “sandbox” using system.DocumentsDirectory or
system.TemporaryDirectory and not trying to write somewhere else (like the user’s home directory, for instance) the “sandbox” entitlement which is applied automatically for App Store builds will suffice. The code would be the same for OS X as it is for iOS.
I choosed to port one of my small simple games, which i expected to be relatively easy.
It was, only a few tweaks here and there and it just works 
It’s called Lunar Lander Relaunched, here is the the link:
https://itunes.apple.com/us/app/lunar-lander-relaunched/id1022272999
Our game is live on MacStore: https://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=1029622460&mt=12
Royal Heroes -strategy - we kickstartered it, btw.
Promo codes: KAXTRE3K4ARY K9YAHX6L7KYP RYYY4EPYM43R HL6ERHFF6YNE 96JL739EJNJE