I've added a little slice of the "engine". At the title screen, press Start and you'll go to a blank maze where you can move the sub up, down, left and right (but not diagonally.) There are no borders, so once it goes off the screen, if you press the opposite direction it was going, it will come back. I have absolutely no idea how I'll do the maze walls, but if something like VUE Snake can be done (with blocks making up a snake), I bet it might be doable.Click here for the latest version.