It includes the source code for the paperdolling engine that is used in the game. Some things don't work because it's a work in progress. It includes a full world editor and script editor. Everything is pretty much ready to go 'cept for the server, and the server code to track enemies and items and user accounts and stuff.
Ha! Whoops! It's supposed to be an MMORPG but it's in the early stages.
Right now it's just an online platformer with no enemies. It took a lot of time to get it to this point too. kinda sad in a way. The hardest parts of the code are done though. Really all that's left is to make quests and an inventory system and enemies.
It's got a full editor if you checked it out already, it's got an undo/redo system and some other interesting features.
If you open the editor you can load some of the maps from the demo and play around with them. Also check out the script editor.