I keep adding them to one program for myself personally. Something that doesn't need to close and re-run but the first one "Are the shapes moving one after another ?" doesn't clear - it stays in VDP I guiess or someplace and just runs on top of the others (the two moving rectangles). So perhaps I can add that to the bottom of the list with a special note that the program will quit after running that particular illusion. Unless someone knows of a command I can use in XB that will clear the proper memory regions.
You should be able to use this to get rid of the 2 sprites: