Everything old is new again
"Once you're done your creation, you can save it to cartridge and send it to other Bangai-O Spirits owners in a very unique way: through the power of sound. Using old-school modem-like technology, you'll convert your levels into a sound that other Bangai-O Spirits carts will recognize. Place a set of headphone earpieces to a DS microphone, plug in the 1/8th inch jack to the host, and send that file off through high-pitch whines. It's similar to the way that we Commodore 64 and TRS-80 programmers used to save and load our created programs, and here it makes a return in a contemporary game design."