This one is very easy, just a first level to mainly get you used to the controls. You start as Peter, in the living room with Edmund. You have to go find your sisters Susan, and Lucy upstairs. As you head upstairs, you can punch some furniture to get coins, which is useful to spend on special moves. But don't spend all your time punching furniture, as you are timed. When upstairs, you will first find Susan in a bedroom, she's has a flashlight with her. Switch your character to Susan, and head to the room across the hall. Use Peter to smash through the door. Now search the room for Lucy. She isn't hard to find. Then a cutscene shows a part of the floor giving way. You must use Lucy to tip toe across because she is the lightest person. You could also use Edmund to do this. Then knock over the Grandfather clock to help the others get across. The next room you come to, you will need to use Edmund to climb the pole and pull it down, so it creates a path across another floor. Return downstairs to find a fire blocking you from getting to the mother. Use either Susan or Peter to move furniture over the flames. Enter the kitchen where the mother is. Use Susan and her flashlight to find the key to get out of the house. There will be a cutscene, and the mission is over.
Remember to collect some coins. Some are hidden, and some are right in your path. Don't bother with trying to collect shields yet, you can come back and do that later to complete 100%.
You can now purchase special moves.