Once Finished downloading you click on My Favourites and then its gets very interesting because thats when the Gameboy Advance Pad kicks in, basically you can try all the games before you flash to a cart and to be very honest the GBA Pad was excellent, playing Mario Kart on it was great and much better than any normal controller you get for PC,
Read the rest of the review of this new flash cart for the GBA (and it also works on the NIntendo DS) on this PAGE.