This project is for practicing CONDITIONALS. Create a number of scenarios, each of which leads to two others. When you’ve finished, readers can choose which path they want to take, and by the end their story experience will be different from others.
Encourage your students to think of some inventions, giving them a project to pour their creativity into. Different tasks throughout the project focus on different aspects of English, so this project can be used as a practical example for introducing new topics, or it might be a good review.