Irem

Established in Osaka, Japan, by Kenzo Tsujimoto, the developer initially focused on manufacturing and distributing arcade cabinets before transitioning fully into game development. The company's early hardware innovations and game designs helped shape several genres. In 1985, the company expanded its reach on home consoles with the release of Zippy Race, a pioneering overhead motorcycle racing game, and 10-Yard Fight, a highly influential early American football simulation that received multiple cartridge printings, including the collectible five-screw design for the Nintendo Entertainment System.

During this same period, the developer adapted its martial arts arcade concepts for home audiences, resulting in the Japanese release of Spartan X and its Western counterpart, Kung Fu, which became foundational titles for the side-scrolling beat 'em up genre. Following a major corporate restructuring in the late 1990s, the game development division reformed as Irem Software Engineering. This modern era produced diverse intellectual properties, including the survival adventure series Disaster Report and the tactical role-playing game Steambot Chronicles, before the company shifted its primary focus away from traditional game development toward pachinko slot machines.