Front Line (フロントライン, Furonto Rain) is a military-themed run & gun shooter game released by Taito for arcades in 1982. It was one of the first video games to feature a ground combat theme and grenades, a precursor to many similarly-themed games of the mid to late 1980s. The original arcade version of Front Line consists of a joystick, a single button, and a rotary dial that can be pushed in like a button. The single button is used to throw grenades and to enter and exit tanks, while the rotary dial controls and fires the player's gun.
The game was created by Tetsuya Sasaki. He was influenced by Space Invaders and Galaga. 1985's Ikari Warriors follows the conventions established by Front Line, including the vertically scrolling levels, entering/exiting tanks, and not dying when an occupied tank is destroyed.