Thunder Force IV (サンダーフォースIV), known in North America as Lightening Force: Quest for the Darkstar, is a 1992 side-scrolling shoot 'em up video game developed and published by Technosoft for the Sega Mega Drive/Genesis as the fourth installment of the Thunder Force series. The game was released in Japan on July 24, 1992, in North America in September 1992, and in Europe in December 1992.