public void moverContinuamente() {
        while(!gameOver) {
            try {
                Thread.sleep(100);
            } catch (InterruptedException ex) {}
            if(panel.x + panel.diametro > panel.getWidth() ||
                    panel.x < 0) {
                incX *= -1;
            }
            if(panel.y + panel.diametro > panel.getHeight() ||
                    panel.y < 0) {
                incY *= -1;
            }
            panel.x += incX;
            panel.y += incY;
            panel.repaint();
        }
    }