Help with 1.3 update for Mac

[xxjaz1228]

I actually went ahead and just downloaded it. I didn't replace it with the old one, it's just its own thing. I was able to test run the new Amnesia application, and it brought me to the loading screen like normal, however I did get a pop-up on the desktop with the header reading,
'"Amnesia" is not optimized for your Mac.'
And underneath it reads,
'This app needs to be updated by its developer to improve compatibility.'
I'm not sure if maybe this Mac is just a little old for the update and/or if this means that I'm gonna experience issues with the new download. Not sure if anyone knows what this pop-up means ?