Hmmm, interesting theme for a game. This could be a lot of fun. My Grand daughters would probably love something like this.

How about an opening scene where you're playing baseball, hit a high fly, and it drops in the attic window, of "that creepy old house" that every second block seems to have. Your game centers around trying to get your ball back.

In order to get your ball back, you have to go into first, the creepy yard full of strange plants and creatures, then enter the scary, victorian style house through the back door. the path to the backyard is rife with man-eating plants and cast-off experiments from Uncle Fester.

Once you enter the house, you meet the creepy but kooky inhabitants, and have to do odd chores for them, find keys, bring them stuff, and generally, do some of the whacky things that have been done in their movies, TV series and cartoons.

You start on the main floor, hit the dark and cobweb infested basement, go up to the 2nd floor, third floor, and finally the attic, to get the ball. Each floor could contain 1 or 2 levels, characters and quests.

There ya go. Basic game idea. This one, no charge... LOL
Watch out for copyright on this, and make sure that you don't get your butt sued.

Cheers!
Mark