Commando
Battlefield of the Wolf.
Placing Commando in the shoot-'em-up category is almost reason for debate. The ground based game mechanics and army assault theme naturally lent it something of a run 'n' gun lilt, yet when broken down into its raw components, we can see that game design legend Tokuro Fujiwara was keeping to a well established and, certainly in 1985, the single most popular style on the arcade floor - the shoot-'em-up.
Brazenly storming enemy territory with your solitary war machine warrior was an arduous and difficult task, but one which yielded an embarrassment of gaming riches for coin slot junkies who were becoming increasing jaded with space based vertical scrollers.
In some respects, Commando should be marked down on technicalities, since there were no upgrades for the main character's weaponry and the enemy variance was undeniably limited. But these elements weren't simply overlooked - they were traded off. While Super Joe (aka "The Commando") had naught but an everlasting supply of machine gun bullets and a few iron pineapples, the standard, vertical scrolling field and waves of enemy drones following predefined attack patterns were cleverly camouflaged in the layered warzone environment.
A space ship might not be able to convincingly hold its position and dig into a defensive barricade, a foot soldier can enjoy that luxury without breaking character - an element used to great effect by the maestro Fujiwara. Breaking through bottle neck defences (watch out for the enemies on the stockades) and skilfully landing a grenade under the tracks of a tank made Rambo's and heroes of us all.
When the characters fit their surrounding so naturally and seamlessly, all evidence of a standard fare shooter disappear into the beautifully realised story of one man on a highly entertaining mission of genocide.