Red Light, Green Light. To move, P1 uses z, P2 uses c, P3 uses b, and P4 uses m. Click the HMN or CPU button to toggle the computer's level or if the player is human or a computer. Green is easy, yellow is medium, and red is hard. Click the button that says Medium to change the difficulty. If you move during a red light, you have to go back to the start. Have fun! Please tell me any glitches you find.