Not bad, but certainly could afford to be more intuitive. I don't think I really even got past the first level because the ball never started rolling after hitting the "start reaction button". Honestly I'm surprised I even got past the tutorial because I didn't realize when it said "hold down the mouse cursor to move the camera" it meant the right mouse button, not the left one. The concept of dividing the tutorial between different rooms was a good idea though. It assures that the player has some idea of the basic controls before they start the game.