Written Python 3 with tkinter module. Your default Python distribution may not include this module, please consult the Internet.
On Ubuntu, this works (but you may want not to install packages system-wide):
sudo apt-get install python3-tkESC to pause, UP to rotate clockwise, Left Ctrl+UP to rotate CCW,
Left Shift+UP to rotate by 180°, DOWN to speed up falling, LEFT/RIGHT to move.