How do you start this up on a mac, it just wont open for some reason.
Assuming you downloaded the ultralight, the folders are in the wrong place. Here's what to do:
Right click on the application --> 'Show Package Contents.
go into Contents > Resources. There should be a folder called 'lib' and a file called 'icon.ins' in here.
Create a folder called 'autorun' in Resources. Put 'lib' and 'icon.ins' in autorun.
In a second Finder window, open up the main game folder. Drag everything except the application itself and the changelog into autorun (that should be the game folder, the renpy folder, the update folder, DDGame.py, and DDGame.sh).
Now double click the application, and it should work.