By typing "max" or "2max" or debug version:

To start - M key
To stop - 2 key

Changing the ball's speed and returning back to the ball's normal speed (movement)

Press M key 1st time - Fast (50 mph per hour)
Press M key 2nd time - Faster (100 mph per hour)
Press M key 3rd time - Double (200 mph per hour)
Press M key last time - 500 mph per hour (Sometimes can't see the ball with eyes)
Press the 2 key - Returns back to normal (5-25 mph per hour)