Wolfenstein 3D

In the game, B.J. is captured, but overpowers a guard with the help of a concealed knife and manages to get out of his cell. Throughout the next nine levels, the player guides B.J. searching for an escape from Wolfenstein, guarded by Hans Grosse. After returning to Allied territory, B.J. is given the instructions to Operation: Eisenfaust, where he has to stop Dr. Schabbs and his army of mutant prototypes before they are released into the battlefields. The final mission has a simple goal: infiltrate the bunker under the Reichstag, and terminate Hitler (in a robotic suit) himself.

The Nocturnal Missions are focused on the Nazi plans for chemical warfare, and start with Dark Secret, where B.J. hunts for lead researcher Dr. Otto Giftmacher. It's followed by Trail of the Madman, where the goal is capturing the war plans guarded by Gretel Grosse, and the final episode Confrontation, where B.J. meets General Fettgesicht, the planner for the chemical assault.

Each episode has nine levels (eight regular and a final boss level), plus a secret level activated by a hidden switch somewhere in the eight first levels. Regular levels often feature a maze-like appearance or large areas with many enemies, where the player must reach the exit elevator. To do so, he must kill the enemies, and depending on the level, activate "push walls" and/or get silver and golden keys to open certain doors.

Many objects can be found in a level, from medikits, chicken meals, and dog food (to restore health), ammo, and treasures, which solely exist for points. There are four weapons (knife, pistol, machine gun, and Gatling), all of them using the same bullets except the knife. The player has a number of lives; once he loses the last life, the game ends.

To win extra lives, the player has to either find the 1-up item in the level or get 20,000 points (by killing enemies and capturing treasures or completing a level below the 'par' time while killing all enemies, finding all secrets by pushing walls, and collecting all treasure points).