The emulator is a port of Visual Boy Advance which was in turn ported to the GP32 by Chui and then Troy Davis ported the emulator to the Dreamcast Console.
The release comes in plain, and a rom image downloads and also the source code is available for anyone to carry this project onto greater heights.
heres some info from this release:
Colors for gbc are not right
you can only load 1 rom per session, locks up if you return to menu and try to start a second rom
Sound is not quite right either, clicks and sputters occasionally disable sound fixes that

Download the first GBA emulator for the Dreamcast from Here. (Emulator is not on GPFs website)
Please give feedback on compatibility etc.