Update 2 - Undoing Things

Updating a game after 3 years must mean it's a pretty beefy update.

You would think, but this is not one of those updates. I've added an undo movement feature that is pretty common in sokoban games and removes the annoyance of restarting the entire level after making a slight error. I tried to get this working initially but couldn't get it just right and then I forget about it. But, the other day I remembered and decided to add it.

Enjoy undoing your mistakes!