I re-installed it this morning (though I skipped copying over the 'movies' from the disk, so that could explain the lack of the hyperionvideo.library being installed).
The registration number is asked for at the end of the install process. Pretty sure what it does is check something, then decrypt a data file to create the Freescape.exe file (it is not on the disk itself, so I assume it's in an archive). If I miss type the serial or don't use capitalization, then it says it's malformed, so at least I know my serial number should work.
Isn't a lot of documentation with it.
My signature has my specs, but if you have that turned off;
A4000, Cyberstorm PPC (128mb RAM), Mediator, ZorRAM (128mb), Voodoo 3, FastEthernet, Spider. Running on the SCSI off the Cyberstorm.