Neat idea and, good-looking / sounding, but I found the difficulty curve, despite the simple mechanics, scaling way too hard with the introduction of the different modes. Maybe make shapes start out somewhat slower, and cycle through modes less fast at the beginning? By the time you get used to one, the next mode starts :^ Also the reverse keybindings mode makes me furious :(
Good work, it definitely is an interesting idea and take on the theme!