Berzerk is a multidirectional shooter arcade game, released in 1980 by Stern Electronics of Chicago. Berzerk places the player in a series of top-down, mazelike rooms containing armed robots.
The player controls a green stick man. Using a joystick and a firing button that activates a laser-style weapon, the player navigates a simple maze filled with many robots, who fire lasers back at the player character. A player can be killed by being shot, by running into a robot or an exploding robot, getting electrocuted by the electrified walls of the maze itself, or by being touched by the player's nemesis, Evil Otto.
The function of Evil Otto, represented by a bouncing smiley face, is to quicken the pace of the game. Otto is unusual, with regard to games of the period, in that he's indestructible. Otto can go through walls with impunity and hunts the player character. If robots remain in the maze Otto moves slowly, about half as fast as the humanoid, but he speeds up to match the humanoid's speed once all the robots are killed. Evil Otto moves at exactly the same speed as the player going left and right but he can move faster than the player going up and down; thus, no matter how close Otto is, the player can escape as long as they can avoid moving straight up or down.
The player advances by escaping from the maze through an opening in the far wall. Each robot destroyed is worth 50 points. If all the robots in the current maze have been destroyed before the player escapes, the player gains ten points per robot. The game has 65,536 rooms (256×256 grid), but due to limitations of the random number generation there are fewer than 1,024 maze layouts (876 of which are unique). It has only one controller, but two-player games can be accomplished by alternating at the joystick.