At Technosoft, he created the original Thunder Force in 1982. Its success launched the Thunder Force series of top-down, free-roaming, scrolling shoot 'em ups, which would become Technosoft's most commercially successful franchise. In 1984, he then created Plazma Line, a space-themed racing game that is considered the first polygonal 3D computer game.
In 1985, he left Technosoft and founded his own company, Arsys Software. In 1986, he created Wibarm, which is considered the first role-playing shooter, combining elements of run & gun shooters, top-down shoot 'em ups, and real-time action role-playing games. The game featured open-world exploration as well as 3D polygonal graphics inside buildings.
In 1988, he created Star Cruiser, a fully 3D role-playing shooter that anticipated the first-person shooter genre, years before Wolfenstein 3D and Doom. In addition to the first-person shooter combat, Star Cruiser also featured open-world exploration with six degrees of freedom as well as visual novel cut-scenes.
In 1989, he produced some of the most technically sophisticated home video games of the 1980s, for the Sharp X68000 computer. One was Knight Arms: The Hybrid Framer, part third-person rail shooter and part side-scrolling platformer, featured some of the most advanced 2.5D sprite-scaling seen on a home system of the 80s. The other was an enhanced port of Star Cruiser, which took advantage of the X68000's powerful hardware to produce the most advanced 3D polygon graphics seen on a home system of the 80s. That same year In 1989, he also ported Prince of Persia for Japanese computers.
After designing Omega Boost in 1999, Arsys Software eventually went bankrupt, and Yoshimura retired from the video game industry as a result.