The bug reported by MacGuges has been fixed, and the new version of the installer is now available for download.
When I just downloaded the game, I could not get it to start. The console log complained that it was unable to locate pygame, which I knew a little bit about, so I looked around for it on my system. It was installed on my system, so that was not the cause of the error. But, I found that a path problem was the source of the error.
Steps to make it work (on my Powerbook, OS X Tiger):
site-packages to site-packages.go.away and then rename site-packages.1 to site-packages.Played the 60 minute demo, then bought the game, and loved it very much.