A random city / village / interesting area is generated.
You start in the middle with one or more missions. (For example: steal food for your family.)
From the moment you do something “wrong”, you attract the attention of the police, and you must try to stay out of sight and escape. This attention will keep increasing, you will get more and more people after you, and you will have to move through the city faster and faster. (Jumping from roof to roof, running into alleys, going into buildings, out of buildings, stealing someone’s bicycle, taking a fire escape ladder, etc.)
Eventually you complete the level if you have completed the mission(s) and you have successfully gotten out of the city.
This idea is inspired by the LEGO game of Indiana Jones. In it there is a level where they walk across the tops of roofs in Cairo, and swing back and forth with the lasso, and go over wooden planks to other sections, etc. It looks very cool and plays nicely.
The city will be randomly generated every time. This is important. This ensures that you do not have a fixed route or hiding places. Instead you must move quickly, react quickly, and think creatively. You must explore the city beforehand before you get too much police after you, and already create some help spots for yourself. (For example, hiding a weapon in a fixed place, or stacking a few barrels so you can climb up somewhere.)