Pathfinding algorithm- an algorithm that finds its way toward a target. It's not the best one out there- but it does work. Unfortunately the way I've implemented this requires that it use the pen (and the little black dots you see appear on your screen when you run it). I am, however, planning on changing this in the future. You can move the blue target to anywhere on the stage, although note that moving it inside of one of the grey areas will break the project (it's impossible to pathfind to something inside a wall).
