Hmm, you ask for a story? This is tough, most children don't really follow a storyline (just watch "Blue", there is no story at all, but tries to teach different languages to very small children).
An I dea I had some time ago, but never did (feel free to use it):
The Animals gone missing (can be on a farm, in the jungle or whereever) and only their shadows are left behind. You are able to bring back the Animals associating the shadows with the animals noises (could be either by clicking while the animals noise is played or maybe have a soundbank and you have to drag/drop the individual sounds on the correct shadows). If the sound fits to the shadow, the animal appears again.