For muilyplayer on VBA i tried plaing a VBA game and i couldn't get it to work and i got it working on singal compter.adn does it matter if theres more than one compter connened to you interened conntoin.
here the link to the link emulator i used.

http://www.vbalink.info/download-gba-emulator.htm

plus heres there torrent how to use it.

http://www.vbalink.info/vba-link-lan.htm