Robotron: 2084 (also referred to simply as Robotron) is a twin-stick shooter video game developed by Eugene Jarvis and Larry DeMar of Vid Kidz and released by Williams Electronics for arcades in 1982. The game is set in the year 2084 in a dystopian future where robots have turned against humans in a cybernetic revolt. The player's goals are to defeat endless waves of robots, rescue surviving humans, and earn as many points as possible.
Jarvis and DeMar drew inspiration from Nineteen Eighty-Four, Berzerk and Space Invaders when designing Robotron: 2084. The pair designed the game to instill panic in players by presenting them with conflicting goals and having many on-screen projectiles coming from multiple directions. A two-joystick control scheme was implemented to provide the player with more precise controls, and enemies with different behaviors were added to make the game challenging. Following its release in arcades, Atari ported the game to several home platforms in the 1980s. It was later included in many retro gaming collections.
Robotron was critically and commercially successful. Praise among critics focused on the game's intense action, control scheme, and colorful visuals. While its challenging gameplay proved popular, commentators acknowledged it catered to select players. Though not the first game with twin joystick controls, Robotron: 2084 is cited as the game that popularized it in the 1980s; the design later saw a resurgence in the 2000s. Jarvis used the same control scheme later in the 1990 Smash TV. Robotron was ported to numerous home systems, most of which lacked the arcade's control hardware. It is frequently listed as one of Jarvis's best contributions to the video game industry.
Gameplay
Robotron is a twin-stick shooter game in which the player controls the on-screen protagonist from a top-down perspective. The game uses a two-joystick control scheme; the left joystick controls the on-screen character's movement, while the right is used to fire the character's weapon in specific directions. Both joysticks allow for an input direction in one of eight ways. The game is set in the year 2084 in a fictional world where "Robotrons" have, after a robot uprising, eradicated most of the human race. The main protagonist is a super-powered genetically engineered mutant who attempts to save the last human family.
Each level, referred to as a "wave", is a single screen populated with a large number of various enemy robots and obstacles; types range from invincible giants to robots that manufacture other robots. Coming into contact with an enemy, projectile, or obstacle costs the player one life; more lives can be earned at certain point totals. Waves also include human family members, who can be rescued to score additional points, but certain robots can either kill them or transform them into enemies. Destroying all vulnerable robots allows the player to progress to the next wave; the cycle continues until all lives are lost.
Development
Robotron: 2084 was developed in six months by Eugene Jarvis and Larry DeMar, founders of Vid Kidz. Vid Kidz served as a consulting firm that designed games for Williams Electronics, whom Jarvis and DeMar had previously worked for. Under the working title Robot Wars, the pair used a Gimix 6809 computer to write the game's program in assembly language. Jarvis and DeMar playtested the game themselves and continually tweaked the designs as the project progressed. The game was designed to provide excitement for players; Jarvis described the game as an "athletic experience" derived from a "physical element" in the two-joystick design.
After spending 18 months working collectively on Defender and Stargate, the developers desired a new creative focus and chose robots. The game was first inspired by Stern Electronics' 1980 arcade game Berzerk and the Commodore PET computer game Chase. Berzerk is a shooting game in which a character traverses a maze to shoot robots, and Chase is a text-based game in which players lure text characters into obstacles. The initial concept involved a passive main character; the object was to force robots chasing the protagonist to collide with stationary, lethal obstacles. As they deemed the design too boring compared to other action titles on the market, the developers added shooting gameplay to provide more excitement. The shooting elements drew inspiration from the 1978 arcade game Space Invaders, which had previously inspired Defender, their first arcade game.
Though contemporary games began to use scrolling to facilitate larger levels, the pair chose a single screen to confine the action. Jarvis aimed to outdo the tension in Space Invaders as the aliens crowd the player. To instill panic in the player, the protagonist is initially placed in the center of the game's action and must deal with projectiles coming from multiple directions, as opposed to previous shooting games, such as Space Invaders and Galaxian, where enemies attack from a single direction. This made for more challenging gameplay, an aspect Jarvis took pride in.
The developers felt a rescue theme similar to Defender was needed to complete the game and added a human family as a method to motivate the player to earn a high score. The additional aspect forced the player to constantly reevaluate their situation to choose the optimal action: avoid enemy attacks to survive, defeat enemies to progress, and save the family to earn points. Inspired by George Orwell's Nineteen Eighty-Four, Jarvis and DeMar incorporated an Orwellian world into the plot. Since the year 1984 was approaching, they decided to set the game a century into the future to provide a more realistic time frame for their version of "Big Brother". Jarvis, a science fiction fan, based the Robotrons on the idea that computers would become advanced entities that helped humans in everyday life. He believed the robots would eventually realize that humans are the cause of the world's problems and revolt against them.
The pair placed enemies in different groups throughout the stages to create themes. Early stages are designed to be relatively simple compared to later ones. The difficulty level is designed to increase quickly so players would struggle to complete later stages. In retrospect, Jarvis attributed his and DeMar's average player skills to the game's balanced design. Though they made the game as difficult as they could, the high end of their skills proved to be a good challenge for expert players. The graphics have a simple appearance to avoid a cluttered game screen, and object designs were made distinct from each other to avoid confusion. They chose black as the background color to help characters stand out visually and further reduce clutter.
Enemy designs
Jarvis and DeMar used graph paper and colored pencils to create the initial character designs. The enemy types were designed to exhibit unique behavior toward the player character; random elements were programmed into the enemies' actions to make the game more interesting. The developers spent several weeks play testing to adjust the enemies' behaviors.
The first two designed—Electrodes and Grunts—are the simplest. Electrodes are stationary objects that are lethal to the in-game characters. Based on enemies in Chase, Grunts are simple robots that chase the protagonist by plotting the shortest path to him; they are designed to overwhelm the player with large groups. While testing the game with the new control system and the two enemies, Jarvis and DeMar were impressed by the gameplay's excitement and fun. As a result, they began steadily increasing the number of on-screen enemies to over a hundred to see if more enemies would generate more enjoyment.
More enemies were created to add variety. Large indestructible Hulks, inspired by an enemy in Berzerk and Marvel Comics' Hulk, were added to kill the humans on the stage. Though they cannot be destroyed, the developers decided to have the protagonist's projectiles slow the Hulk's movement as a way to balance the gameplay. Levitating Enforcers were added to provide enemies that could shoot back at the main character; Jarvis and DeMar liked the idea of a floating robot and felt it would be easier to animate. A projectile algorithm was devised for Enforcers to simulate enemy artificial intelligence. The developers felt shooting directly at the protagonist would be ineffective because the character's constant motion would always result in a miss. Random elements were added to make the projectile more unpredictable; the Enforcer aims at a random location in a ten-pixel radius around the character and random acceleration curves the trajectory.
Jarvis devised the Spheroid enemy as a way to further differentiate Enforcers; Spheroids continually generated them, rather than have Enforcers already on the screen like other enemies. Brains were conceived as robots that could capture humans to brainwash them into enemies called Progs. They could also launch cruise missiles that chase the player in a random zigzag pattern, making them difficult to shoot down. DeMar devised the final enemies as a way to further increase the game's difficulty; Tanks fire projectiles that bounce around the screen, and Quarks are Tank-producing robots.
Hardware
Robotron: 2084 arcade machines are based on the hardware designs established in Williams' 1981 game Defender. The hardware features monaural sound and raster graphics on a 19 inch CRT monitor. The machine consists of five circuit boards that coordinate different processes required to operate the game: a main central processing unit (CPU), a read-only memory (ROM) board, a soundboard, an interface controller board, and the power supply. A 1MHz Motorola 6809E microprocessor serves as the main CPU, which executes the game code and assembles the graphics to display on the screen. Sounds are generated in software, with the same routines as in other Williams games of the era. The game uses a priority scheme to determine which sounds to play on a single channel.
The developers added two blitter chips to the Defender hardware in order to improve the graphical capabilities. The blitters generate the on-screen objects and visual effects. Because they transfer memory faster than the CPU, the game is able to simultaneously animate a large number of objects. The unit includes settings to adjust the gameplay difficulty and the point threshold for earning additional game lives. The machine also provides arcade owners with usage statistics, such as the average time per play, which Williams recommended businesses use to gauge when to increase the difficulty setting. A pack of three AA batteries provide power to save the game's settings and high scores when the machine is unplugged from an electrical outlet.
The dual-joystick design was developed by Jarvis. Prior to development, Jarvis injured his right hand in an automobile accident. His hand was still in a cast when he returned to work, which prevented him from using a traditional joystick with a button. While in rehabilitation, he thought of Berzerk. Though Jarvis enjoyed the game and similar titles, he was dissatisfied with the control scheme; Berzerk used a single joystick to move the on-screen character and a button to fire the weapon, which would shoot in the same direction the character was facing. Jarvis noticed that if the button was held down, the character would remain stationary and the joystick could be used to fire in any direction. This method of play inspired Jarvis to add a second joystick dedicated to aiming the direction projectiles were shot. Jarvis and DeMar created a prototype using a Stargate arcade system board and two Atari 2600 controllers attached to a control panel. The final production models use joysticks manufactured by Wico Corporation. In retrospect, Jarvis considers the design a contradiction that blends "incredible freedom of movement" with ease of use.