the n70's cpu is not powerful enough to run GBA games at full seed with soundits not available on pc...
and why do you want to emulate a celphone game on pc??
i have sega emulator on my cellphone(picodrive) which runs full speed and sound.. its a freeware(jope i can share it here, and hopes its not agains the rules..)..
i have vbagx which is a gba emulator for s60 phone(bought it)
vnes is an nes emulator for s60
vsun is an emulator for snes
vboy is a gb and gbc emulator for s60
i have a s60 phone.. 2nd edition (my phone is n70)