The rough video above shows how it's possible to reduce the number of controls needed to play a game. In this instance, four controls have been reduced down to a single button/switch.
Using a switch interface on a PC running the latest 4Noah utility alongside MaxAim, all kind of things are possible.
With Peggle, one-switch works as follows: Tap to change the aiming angle (left - stop - right - stop). Hold for a couple of seconds then release toggles between fine aiming and fast aiming. Double-tapping fires the ball. I feel a Gaming Redux section coming together.