Well they have already confirmed Neo Geo VC releases, and I'm pretty sure the later titles are around 70MB or so. I'm pretty sure Dracula X would be half that size, of that, as long as they MP3ed the music.
Neo Geo Roms are typically between 10 and 30MB. Example: Fatal Fury is 4MB, Fatal Fury 3 is 19MB, KoF '99 is 22MB, Metal Slug is 13MB, Metal Slug 2 is 18MB, etc. N64 ROMs are typically in the 20MB range.
DracX MP3ized with 128kbps MP3 comes to 80MB. There is actually significant difference there that wasn't obvious to me until I wrote these numbers down
The actual game data of even the hugest PCE CD is incredibly small. Much much smaller than, say, N64 games, which they are already doing.
Erm, well, not really. Monster Lair is the one of the smallest games MP3ized, coming in at 66MB, definitely a lot larger than an N64 game - the largest N64 ROM I have is 32MB, half the size of Monster Lair.
OD