Shapes made corner by corner with createGeometry: where each corner is, and which three make each triangle, counter-clockwise from the side that is drawn. Behind, the same star twice, its facings worked out smooth on the left and flat: true on the right, and a ramp with a colour painted at each corner.
Hold the button down on the field and it sinks there: updateGeometry writes the corners over what the card already holds, and only while they change. The comet's trail grows a step every frame until it is as long as it goes, outgrowing the room its shape was given, and is given more.