Heavy Barrel

Heavy Barrel (ヘビー・バレル) is a 1987 overhead run and gun arcade game by Data East.

Gameplay

Terrorists have seized the underground control complex of a nuclear missile site, and it is up to the player to infiltrate the base and kill the enemy leader. Players begin armed with a laser gun with unlimited ammunition and a limited supply of grenades. Improved weapons and grenade powerups are made available within the game, either in plain sight or within crates that must be unlocked using keys. Additionally, crates may contain orbs or one of the six pieces of the Heavy Barrel superweapon. Like SNK's Ikari Warriors, the original arcade version featured rotary joysticks.

Source: Wikipedia, "Heavy Barrel", available under the CC-BY-SA License.