In the past I have posted tutorials for how to use Scratch to create a ball-and paddle computer game, but I let Carolyn create what she wanted to create. Rather than targets to shoot or puzzles to solve, she chose to tour a virtual environment, via a self-paced storybook. You move ahead by clicking the screen, and invisible buttons trigger animations.
This tutorial is a good introduction to how easy it is to make something interactive in Scratch.
Carolyn started with photos she had already taken of her Lego hobbit hole, added some simple programming to make a click advance to the next screen, and to make an invisible button trigger some animation.
In the video, she’s careful to run the program after every couple of steps, and she catches a few mistakes. When I point out that an interactive detail she coded would be hidden from a player who didn’t know where to click, she added a label that made sure her players wouldn’t miss the interactive bits.
If your browser runs Flash, you can play the game yourself below.
Carolyn learned Scratch by working her way through the book Super Scratch Programming Adventure.
(I am still teaching with interactive fiction playthrough videos that I recorded when Peter was about the same age as Carolyn.)