A few years ago a friend of mine came up with a nice sliding block puzzle game. As a quick learning exercise I've written a WRT implementation of it, which you can download here. If you like puzzle games like Sokoban then this might be interesting to you.
I'm planning to support some better known related puzzles (Sokoban is the main one, actually, and is mostly done), so I'd really appreciate feedback about the current widget before I put any more effort into it.