The circuit for the RetroGame is really pretty simple.
The software, on the other hand, is rather complex.
It is written in assembly for the PIC 14-bit processors.
It would run on any 16CXXX device, but is specifically
targeted toward the 16C622 for this application.
Note: The software compiles easily and cleanly on the latest MPLAB IDE v8.20.
On some previous versions the IDE may complain. If this is the case, first remove the
".mcw" files before compiling. There are two: "Retris.mcw" and "RetroRover.mcw".
If anyone truly wants a description of the software, I'll be glad to write it!