if you have an idevice, be it iphone or ipod, and you are jailbroken, add the source "xSellize" in cydia and search for "gpSPhone", which is a game boy/Game boy advance emulator and then within the emulator, just search for whichever GBA game youd like and play it in the emulator. Hope i helped :D

PS if i were you id get the Metroid games, theyre awesome.