Scratch

I worked on this a while ago. Although when I saw shadow_7283's project, and I told them I was working on this, than they sorta got desprate saying 'Upload this please!'. So I finished this, and uploaded this.

This is A* pathfinding for scratch. It is based on a 11 by 15 grid, and it works pretty well. In mode one, you can click on tiles to change it between a block and no block, and use left and right arrow keys to move the start block, and A and D to move the destination. In mode 2, it will actually go to the place. If you close it all up, it's smart enough to say 'Error!' and stop the project. Its not perfect, but its the best you can find in scratch.

Keep in mind though, that only use this method of pathfinding, for scratch games that are tilebased. If you want to make a different non-tilebased game, which requires pathfinding, use http://scratch.mit.edu/projects/AddZero/186736 , Addzero's AI Navigate 1, which can be used for racing games. tower defence, etc.

How the A* method works: First it finds out which blocks its possible to go to. this can be from 0 if its all closed in, to 8 if theres no walls next to it. Then it calculates for each one, if it is in a diagonal direction, or vertical/horizontal. If its diagonal is 14 (10 x sqrt. of 2 approx.), or else its just 10. Then it calculates how many blocks it is from the destination. It multiplies that by 10, and keeps track of it. Then for each block it adds the two together, and it goes to the block with the lowest value.

Enjoy!