All the information required is in this repository but it may not be all that clear so here is an attempt at helping out.
As indicated in the home page, there are some requirements for the electronic design files (KiCad)
Make sure that the "tag" of the release is the one you're after and then go to the DesignFiles folder and download all the files in it. The only file missing is the "brd" from the KiCad bundle but in its place there is the GERBER files for manufacture. The "sch" files are the ones you're after if you want to tinker with the design.
As indicated in the home page, there are some requirements for the firmware (Arduino) environment.
The core of the unit is an ArduinoPro Mini microcontroller and the firmware to program it with is under the PACMAN/ArduinoProMini folder. The firmware for the auxiliary ATtiny85 microcontroller is in the PACMAN/ATtiny85 folder.
The enclosure design file is included in the DesignFiles folder and corresponds to the SVG file for a laser cut service on 3mm acrylic. The file format (but not size) is compatible with the service provided by Ponoko.