I was inspired to make my own version of this classic puzzle game, after viewing @RokCoder's two versions (see links below). I tried to keep the code simple, to serve as an example. See inside. All code by me (@kriblo). Wait until it's done shuffling, then try to sort the numbers by clicking a tile adjacent to the gap. "Fifteen 3D (20000 followers)": https://scratch.mit.edu/projects/1049823219/ "A simple implementation of the classic game of fifteen" https://scratch.mit.edu/projects/1045773817/
Bit harder still.
