I disassembled and poked around inside that 50 MB exe file from the PC CD-ROM verison. At least some of the data seems to be in a different format than the Amiga version. This includes the music, which is plain old Protracker instead of the Digital Illusions format used on Amiga. I extracted the files and submitted them to
AMP if anyone's interested (they're prefixed by "Pinball Illusions PC").