Project Mouse House
You are a mouse who has been chased out of your home by a cat. While running away, you come upon a large house. Having nowhere else to go, you run underneath it into safety. After getting your bearings, you look around your surroundings and find a splinter of wood that seems to glow with power. After some careful experimentation (biting it), you find out it can be used to cast magic.
This is a house owned by a wizard who makes magical wands and staffs for a living. When he is shaving down the raw material, he often leaves a mess of wood and dust on the floor. The scraps have made their way all through the house and affected small animals and insects currently living there, causing them to gain magical powers or use the splinters as wands.
These creatures have spread themselves into several clans, with the Rat clan being the most powerful out of all the other clans. You find yourself among other mice who have been forced into hiding by the Rat clan. You will need to battle the other clans, slowly increasing the Mice clan's power, until you can finally stand up against the Rat clan.