Man. I finally got the controls down.
For missle command, on full screen, I drag the plus sign around with my finger. And then tap the closest missle launcher.
For centipede, in full screen, I drag the shooting bug around with my finger and hold in the scroll wheel for constant firing.
For lunar lander, on full screen, I use the steering wheel to rotate the lander and push the scroll wheel to modulate the thruster.