Lightening Force: Quest for the Darkstar (JP/EU: Thunder Force IV) is a horizontal shoot 'em up and the fourth game in Tecnosoft's Thunder Force series. The ORN Empire from the previous games has resurfaced once again, threatening the safety of the entire human race.
This game contains eight levels, four of which were initially selectable. Players can choose a "Direction of Attack" on the main menu screen, and select which order to approach the first four levels.
This had almost no effect on gameplay.