Click "Start" to see the puzzle board. There are 15 blocks that can slide right, left, up, or down. The puzzle is solved when the blocks are arranged in order as shown. Click "Scramble" to mixup the blocks. Click a block that's next to the empty space and it will slide into the space. Don't try to drag the block. It automatically knows whether it should move right, left, up or down. You can slide multiple blocks by clicking any block that is in the same row or column as the empty space. All of the blocks between the one you click and the empty space will slide toward the space. Keep sliding blocks until you solve the puzzle. Click "Reset" to restore the blocks to the original arrangement. - Don Shaffer
For my first Scratch project, I decided to make a version of the classic "15 Puzzle", which was invented by Noyes Palmer Chapman around 1874.
