Chris Crawford on Game Design

Input Structures

Once I had my screen laid out, I set to work figuring out how the user could control the power plant. Having gotten the problem backward by laying out the screen before settling on my input structure, I was now in a bind. I could figure no clean way to control the power plant with a joystick and cursor. Being young and impatient, I simply barged through the problem with a wretched solution. The game offered eight controllable devices: four pumps (the orange octagons), three valves (the orange X-shaped objects), and the reactor core. Clearly the player would somehow use the joystick to select one of those eight objects, press down the joystick button, and actuate the joystick up or down to adjust the device. But how, exactly, ...