Due to a mastering error, source code and other related assets were accidentally pulled from Alfa System's development machine and were used as the game's padding file. The included files can be found by extracting the code track from the game and searching through the contents for LZH archives. While the source code is mostly complete, some files are corrupted due to hard drive fragmentation of the development machine.
I can't believe they were able to find this! This is a pretty amazing find.