Quick note that due to a mistake I made in previous OS X builds, MMORPG Tycoon wouldn’t run on OS X 10.4 as I claimed it would. I’ve put up an 1.0.7 build for OS X which adds 10.4 compatibility.

If you’re running OS X 10.5, there’s no reason to upgrade; there are no major changes other than 10.4 compatibility.