I wrote a basic Sokoban as a demonstration of how to use Decker to make turn-based puzzle games:

Try it here!

The game takes place on a single card, using the "navigate[]" event to capture arrow key presses and buttons with shortcut keys for reset/undo. Level data is stored in a series of other cards, with goals and passability information encoded directly into the background image as specific patterns. The player and boxes are represented with instances of a Contraption called a "mover" which encapsulates tweened animation and cycling through animation frames.

Feel free to pick this example apart and use it as a starting point for your own creations

Looks really fun!

very nice and smooth.

i would like to learn more about how to write different tween functions. is there a way to code something like a brief screen shake? maybe throw some widgets around a few pixels at a time. 

thanks!