Wolfenstein is a first-person shooter game that follows B.J. Blazkowicz, an Allied spy, as he navigates through the Nazi-occupied territories. The story takes place in six episodes, with each one revealing more about B.J.'s mission to stop Dr. Schabbs and his army of mutant prototypes from releasing a deadly chemical warfare agent. Throughout the game, players guide B.J. through nine levels, searching for an escape from Wolfenstein Castle, where he is being held captive. After escaping, B.J. receives instructions to carry out Operation: Eisenfaust, which involves infiltrating the enemy's bunker and terminating Dr. Schabbs. The final mission takes him to the heart of the Reichstag, where he must face off against Hitler in a robotic suit.
The game also features three Nocturnal Missions that delve into the Nazi plans for chemical warfare. These episodes focus on B.J.'s pursuit of lead researcher Dr. Otto Giftmacher and his mission to capture war plans guarded by Gretel Grosse, ultimately leading him to face off against General Fettgesicht.
The gameplay involves navigating through maze-like levels, fighting enemies, and collecting items such as medikits, ammo, and treasures. Players can collect silver and golden keys to unlock doors, activate "push walls" to progress, and reach the exit elevator. The game features four weapons, each with its own unique characteristics.
Players must manage their health, as they can lose lives by being killed or running out of time. To win extra lives, players must find hidden items such as 1-up power-ups or accumulate points by killing enemies and completing levels quickly.