I made a little demo of source code for making a sliding letter puzzle for newbies to Wintermute and coding. It includes using a particle maker and an overlay. Overlays are cool and they are really easy to use. You just have to remember to check the box that makes an object "interactive" or your overlay will be dead. : ) How many times I have forgotten this. In fact, I wish it were the default that the object is interactive.
It can be tweaked to do other things as well, f.e., a picture puzzle, putting together a torn letter puzzle, and many things you could imagine.
http://forum.dead-code.org/index.php?topic=3761.0Thanks to The Derman for the sliding part, thanks for everything else to Mnemonic. : ) Thanks to Maze for reminding me of X's and Y's from an old post of his and for reminding me that it's nice to put everything back as it was if player doesn't get it right. : )