This is a sliding puzzle game with 100 puzzles and a level editor. (I'm not sure where you would find more levels for download, but apparently you can?) The twist is that you can only slide the piece you're on, so the game introduces mechanics for you to switch tiles: you can use a ladder, teleport yourself, switch out the level, and more. There are also locked doors, keys, explosives...
But wait, there's more, it gets meta. At the same you are moving the tiles, you also need to place them correctly so the background picture will look right in the end. If you manage that, you unlock items. And even more meta: these items can be used in a small point&click that is framing your puzzle endeavours.
It's all wrapped up in some photographic art that, despite being 1024x768 (the game scales it up for you if you like) does the job admirably, as does the slightly jazzy music that gives the game an old-time London feel. But you can see that from the trailer and the screenshots.
Solid puzzler, lots of (up to now) casual puzzles that provide a soft learning curve, and are orginal and fun to do. It took me about 1 hour for the first 20 levels of 100. I'm definitely going to finish this game.