Heavy Barrel

Heavy Barrel is a 1987 overhead run and gun arcade game by Data East. 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.