So you would like us to make the whole game story for you based on the adams family?

First off try thinking of your own ideas, dont expect other people to do it for you, just try to think of something unique , maybe even a bit crazy/experimental (its your game, do what you like)

And here is one idea, start off outside the house, and the first bit can just be a tutorial where they run around the inside and outside (soom rooms locked untill later on), and they can just do some crazy things and see some crazy things, and they may have to approach someone (from the family) to get there first kinda quest...