press SPACE to start the rotation. press R to reset. press C to clean the canvas without resetting. dr2 is the rotation speed of the pink line. dr3 is the rotation speed of the orange line. you can change dr2 with: J and K. you can change dr3 with: N and M.
inspired by Engare game. youtube video of Aliensrock on the game: https://www.youtube.com/watch?v=LX9DKo7bgSg