Green flag. In automatic mode, will automatically morph from one shape to another random one. Press space to toggle manual mode, where you can control the next shape using the number keys : 1 - Circle 2 - Square 3 - Triangle 4 - Heart 5 - Star 6 - Trapezoid (thank you @superdude1234567 for suggesting it) 7 - Hexagon(thanks to @Dookler ) 8 - Deltoid (thanks to @qwertyman5 )
Feel free to propose new shapes (preferably with equation/link to equation in case of a complex one), but I can't promise quick implementation ;)