Each level is themed after Nazi bunkers and buildings, though the level layouts are not based on any real locations. To finish a level, the player must traverse through the area to reach an elevator. Groups of levels, typically 10, are grouped together into named episodes, with the final level focusing on a boss fight with a particularly difficult enemy.
While traversing the levels, the player must fight Nazi guards and soldiers, dogs, and other enemies while managing supplies of ammunition and health.
The player can find weapons and ammunition placed in the levels or can collect them from dead enemies; weapons include a knife, a pistol, a submachine gun, and a rapid-fire chain gun.
While the levels are presented in a 3D perspective, the enemies and objects are instead 2D sprites presented from several set viewing angles, a technique sometimes referred to as 2.5D graphics.
The player’s health is represented by a percentage starting at 100, which is diminished when he is shot or attacked by enemies. If the player’s health falls to zero, he loses one life and starts the level over with a knife, a pistol, and eight bullets.
The player begins each episode with three lives and can gain more by finding extra-life tokens or by earning enough points. Points are scored by killing enemies or collecting treasures scattered throughout the levels.