Don't let the orange pass.
Hold to quickly rotate counterclockwise, don't hold to quickly rotate clockwise. you have a green line to help you aim. periodically, the green laser is fired indicated by the green ring and if any enemies are on the line of fire, those enemies die and you get 1 point. The game gets faster by some point, but is capped. if any enemy goes to the other side, you lose with a score of how many enemies you killed.