Okay, the demo has now been fully commented and is now up in the forge. Please note that for the demo to run, you NEED to have build 7721 or later (Justin added in the z-order code block for images in 7719 and fixed a bug in 7721).
The demo itself is a bit bogged down by the menu itself. I tried to make it "pretty", so the coding was a bit bleh. Heck, even making the grid for the pieces visible was a pain in the butt. The good news is that the code for the actual puzzle part is amazingly small. I'd say about 3/4 of the coding was just "bling" and only 1/4 was the puzzle. Furthermore, considering how small the demo is (only two real behaviors), that means the game part is really short.
One thing I never quite realized before making this demo was just how much an image instance really IS just a collision-less (and animation-less) actor. I'll likely be using them a LOT more in my own programming in the future. Also, of course being able to chop up an image in automated ways way pretty nifty too.
Anyways, "Demo Updated Puzzle" is now up in the Forge. Enjoy!