The art bit is what it is, you have to recreate the graphics yourself, but the sound part says it either has to be made by you or be royalty free/freeware sound.
Like the kind you get by searching for 'free sounds' or 'royalty free sounds', theres quite a few websites. Technically that would mean you could use royalty free midis/mp3 for music too.
But you will have to check even at some of the free sounds sites what conditions if any are. Usually they are pretty open and you could sell a game with them, others are only free if your game is free.