It could be integrating additional storage options into your home, discreetly hidden within your staircase. It could be interesting shapes added onto each step. It could also be a few fun aspects, such as an option to slide down instead of using the steps once again in descending from one level to another. You could allow your stairs to shed interesting shadows on the floor, or you could have it doubling as something else like display cases. No matter what interesting addition you choose to have, the entire aspect of creating and designing stairs for any structure just became more interesting.
This is exactly what some contemporary designers want to show, giving some of their creations intricate details that make these sets of stairs not only more aesthetically appealing, but more functional as well.
Reference: 50 Crazy Stairs from Around the World