Well, create a small game that allows you to walk forwards or backwards through rooms (implement as a double linked list). You can also save that linked list to file and read it back properly later too.
The rooms should contain a name and size.
If you want to complicate it EVEN further, then you can create a game with rooms that allows you to walk east, west, north and south, to different rooms to reach the goal. You can also add health and traps in certain rooms. If health reaches 0, the hero dies.
Hint: Add traps and damage they do into the list.
You might also create a struct with hero information such as name, gender and health.
Not the easiest thing to do. I'd call that pretty hard.