Man, I wish this thread had gotten more attention at the time. I've been playing one of the Barcode Battler-compatible games lately, Donald Duck and the Magical Hat, and it was a nice relief to know that -- contrary to claims at other websites about "unlockable content" -- I wasn't missing out on anything by not being able to scan barcodes.

I'd love to know the rest of celerystalker's research; too bad he hasn't posted in a couple years.