the set of files at the web site is apparently incomplete. when combining the files with hacha.exe, the program hangs at 47% of yumemi.33. the resulting short ace file reports the contained file is compressed to 175,766,832 bytes, but itself is only 175,483,512 bytes. the set of files at the site total only 175,483,567 bytes, the first 55 bytes holding information for hacha.exe. so, the ace file contains the number of bytes as there are available for extraction from the set of files. this means there are > 283,320 bytes missing (the rest of the iso file, plus ace header information of undetermined size).
so either the uploader forgot something, or something got screwed up when splitting the ace.
The game DOES work. I downloaded all the files and used that hacha program, which gave me an .ace file. For some reason i couldn't unpack it with Winace, but Winzip did do the trick and gave me an ISO. I tested it with Gens 1.80, and it seems to work.
I don't know if i just got lucky, the dude from the website replaced a file or you guys got 'cooked' files. Anyway, if you want, i can post it in alt.binaries.emulators.sega this week.