In June of 1980, Ken and Roberta Williams completed and self-published their first game, Mystery House under Ken’s company name On-Line Systems. The title not only pioneered the integration of graphics in the adventure game genre but also served as the cornerstone for the renowned Hi-Res Adventure series. The success played a pivotal role in establishing the company as one of the most prominent in the industry.

In May of 1980, Roberta pulled out a $200 full-page advertisement for Mystery House in Micro 6502 Magazine. Alongside Mystery House, the advertisement also highlighted two sports games, Skeetshoot and Trapshoot, both developed by a third party, demonstrating On-Line Systems’ early commitment to diversifying its portfolio beyond the adventure genre. While Skeetshoot and Trapshoot quickly faded away, it didn’t take long before another sports game emerged from the company.

In 1980, Jay Sullivan, a brilliant software engineer who had worked with Ken at Informatics in the ’70s was hired with the original intent of assisting Ken in writing a compiler, but with the initial success of Mystery House, the two changed focus. Sullivan with the assistance from Ken, went on to create two Hi-Res sports games in 1980 and 1981.

The first title, Hi-Res Football was, as the name applies, an American Football game featuring both single and two-player modes. The game was a simple real-time sports game where you had control of both the offensive and defensive plays, featuring actions like runs, passes, kicks, etc.

One of the very first titles by On-Line Systems, Hi-Res Football, developed by Jay Sullivan with help from Ken Williams and released in 1980 for the Apple II

The following year, Sullivan and Ken finalized the development of Hi-Res Soccer, the second and final sport’s title to carry the Hi-Res label. The game aimed to recreate European football, offering players the opportunity to engage in real-time matches against either another human player or the computer. Each team comprised of eight players and employed paddle controls to execute actions such as passing, dribbling, and shooting. Hi-Res Soccer featured three distinct skill levels, catering to players of varying expertise, beginner, intermediate, and advanced.
Similar to Hi-Res Football, Hi-Res Soccer was exclusively released for the Apple II and shared several gameplay characteristics with its predecessor.

Ken Williams and Jay Sullivan went on to create Hi-Res Soccer in 1981 like Hi-Res Football it was only released for the Apple II

Neither of the two sports titles received anywhere near the same success as the company’s adventure or arcade titles at the time. In 1981 Williams and Sullivan co-founded Calsoft, one of the earliest mail-order software stores to carry a full selection of micro-computer software from various publishers, including titles from On-Line Systems and its competitors. While the mail-order business was primarily run by Sullivan he did find time to write Crossfire, a multidirectional shooter inspired by the video arcade coin-ops Targ and Space Invaders and published by On-Line Systems later in 1981. In 1983, Sullivan ported Richard Garriott‘s 1982 title Ultima II: Revenge of the Enchantress to the PC

Following Jay Sullivan’s two Hi-Res sports games he went on to create Crossfire, an action shooter, published by On-Line Systems in 1981.
I’ve written a more in-depth article on Jay Sullivan and Crossfire here