Thunder Force

Thunder Force is one of the classic Japanese shoot 'em ups from developer Technosoft, and from the late 1980s it built a distinct identity within the genre, even though its roots reach a few years further back to Japanese home computers such as the PC-8801, before the series moved fully onto consoles. Instead of scrolling in a single direction, its so-called free-roaming stages let the ship move up, down and sideways at will, which was unusual at a time when most shooters kept players on rails. The second signature was its weapon system, with types such as Twin Shot, Hunter and Free Range that players could switch between at any moment without losing previously collected upgrades, making weapon choice as important as reflexes.

The series peaked with its Mega Drive entries, above all Thunder Force III and Thunder Force IV, released in North America as Lightening Force. The latter is still prized for its speed, elaborate soundtrack by composers tied to Technosoft and inventive boss fights, and many players and reviewers regard it as the best entry in the whole series. After moving to the Saturn, Thunder Force V combined classic two-dimensional gameplay with contemporary three-dimensional backgrounds; it saw only a limited release outside Japan, so Western players mostly discovered it in retrospect, and it became the last major release of the era before Technosoft fell quiet for a long time.

Outside Japan the series long remained a niche concern aimed mainly at genre fans. Only in retrospect, thanks to emulation, later retro compilations and an active speedrunning community, did it earn a reputation as one of the most accomplished and fastest shooters of the 16- and 32-bit generation, inspiring a number of later Japanese and independent shoot 'em ups that kept experimenting with free-scrolling stages.