What kind of game (in Scratch) would require use of a list? I teach an introductory Scratch class to a group of elementary-school students. Most of the focus is on having fun creating simple games, but i still try to introduce a little higher-level programming as well, so that they have the tools when they decide they need them.

What are some relatively easy games that require using a list that i can assign them?
Ideally it should be something that can be done in an hour-long lesson.
A variant on the usual random drill and practice test would be to pre-populate with the questions and answers, then remove question and answer from each as they get answered correctly, allowing players to get more practice on the questions they get wrong. Here's an example for times tables.

You could try something for an adventure game, building up an inventory of items collected in a list. Another possibility would be an adaptive 20 questions style game, adding additional questions into a database (of sorts) as the player gets to the end of a branch of the tree.