Eugene Jarvis took to the stage at GDC to talk about his 1982 Williams arcade hit Robotron 2084, a 2D shooting game noted for its insanely fast-moving action and chock-a-block busy screens.
Robotron was a significant departure for Jarvis and his team, who had previously worked on Defender and Stargate, both of which were side-scrolling space shooters that gave the player lots of freedom of movement. Robotron limited the player to rooms, filled with hostile robots and humans that needed saving. Each level was one room, that needed to be negotiated.
"After the sideways scrolling space shooters, I was burned out and wanted to do something completely different," he said. "Games really are about limitations. In Robotron you are trapped and surrounded on all sides."
One of the game's innovations was its use of two joysticks, so players could shoot and move in different directions. This was married with a large variety of enemies that behaved in odd ways. Variable enemy design was a hallmark of Jarvis' work which, he said, was inspired by "just thinking about all the ways I could kill the player."
But he wanted to create a game that would offer practiced players an opportunity to "play for hours if not days, to be a real hero." Such a player would need to practice a great deal. Robotron is not an easy game to master.
Attendees to his game post-mortem, a popular fixture of GDC in which great game designers look back at their major works, were treated to insights into the code he wrote at the time, and his problem-solving techniques, using technology that was extremely limited. He said that the tech was a kind of liberation, forcing the programmers to focus on delivering fun.
"With games today, we have an incredible richness of creativity and technology," he said. "We can do anything we envision. The classic arcade games, not so much. It was all about gameplay. That's all we had, balance, difficulty ramping, challenge."
Robotron was written in the same year that IBM launched its first PC, which Jarvis called "a piece of shit." His team used a Gimix 6809. In those days, he said, there were no high-level programming languages, Photoshop or APIs. "Everything was written in machine language and you just did your own stuff," he recalled. "But this was like paradise. You just wrote your own stuff and never had to worry about leaning a 400-page programming language manual."
The arcade machine hardware made use of something new in the world, a GPU, although Jarvis noted that the CPU and GPU could not both operate at the same time, due to hardware restrictions.
He said the development process was highly iterative, by necessity. "It was like a game jam thing. It was interactive game design. You started with the minimal design, played it and improved it until it was fun. A game could evolve into something totally different from the original intention. We were seeking out the fun as opposed to following a script."
Robotron became one of the most successful arcade games of the early 1980s and is often cited as a major influence by game designers who were growing up at the time.
Jarvis said that, as a programmer, he was most interested in "creating freshness" so that the rich variety of enemies could always deliver new experiences. In his career, he said, there were many projects that didn't work out as expected. But with Robotron, which took six months to develop, "everything turned out right."