"The Saboteur" is a free-roam, third person action game;
you play as Sean Devlin, an Irish mechanic, and can move independently in the city of Paris, and can complete the main storyline at your leisure. The overall objective of the main storyline is to kill Kurt Dierker, a high ranking Nazi colonel who cheated Sean out of his 1940 Saarbruken Grand Prix win. However, as time passes by, Sean realises that he got himself involved in something far bigger than that; his new goal is to defeat the Nazis and expel them from Paris, in order to stop them getting their hands on nuclear missiles.
The city of Paris (and the surrounding countryside) is full of Nazi outposts, searchlights, radars and other Nazi installations, as well as SOE supply drops. Alongside completing missions and optional side missions, scaling buildings and destroying Nazi installations play an integral role in gameplay, as these earn you contraband, which is a form of currency you can use to buy weapons, ammunition, explosives and upgrades. Even after the main storyline is completed, you can still complete optional missions, races and mini-games, as well as continuing free roaming about Paris, which can unlock you perks and more powerful weapons.
Every action performed by Sean generates suspicion; climbing buildings, setting explosives, getting too close to Nazis, etc. The suspicion meter aroung your minimap will fill faster or slower according to how suspicious Sean's particular actions are. If a Nazi gets too suspicious, he will raise the alarm. If that happens, the Nazis will pursue you until you are dead, or have escaped. To escape, you must leave the red circle on your minimap (which centres on Sean every time a Nazi spots him), use a hiding spot (small green dot on map) or go to a resistance fightback zone (large green dot) and kill enough Nazis while within it.