Here are the controls for Face Hugger's Worm Slickers.

          Red            Green          Yellow         Blue
          ------------   ------------   ------------   ------------
Start     Fire           SPACE          RETURN         Fire/G
Up        Joy. up        A              f7             Joy. up/6
Down      Joy. down      Z              f4             Joy. down/5
Left      Joy. left      X              f2             Joy. left/R
Right     Joy. right     C              f3             Joy. right/T

The red worm is controlled using joystick 0 (the default joystick), and the blue
worm can be controlled using joystick 1.