I used Nathan's Instructable to guide me in building the circuit, and programming the Arduino. It was stone simple.
I marked up the joystick with tape and a sharpie so I could remember the orientation of the controller before I jammed it in the pumpkin - I also machined out some slightly larger holes to make it easier to mount the joystick in the pumpkin.
The Arduino requires the following libraries from Adafruit:
And here is the sketch
A small understanding of how these microcontrollers function is helpful when building these kinds of projects. I had to do a little fussing in the sketch when the joystick wasn't communicating in the way I had initially anticipated.