Every series has an entry where restraint leaves the building. For Metal Slug, that entry is the third one. Released in 2000, Metal Slug 3 takes the run-and-gun formula Nazca and SNK had perfected — one or two soldiers, an absurd arsenal, and the most lovingly hand-drawn destruction in arcade history — and turns every dial until the stops break off. Branching paths. Elephants with machine guns. A mission that goes to space. A zombie apocalypse played for slapstick horror. Metal Slug 3 is not just the biggest game in the series; for a great many players, it is the series, the one against which every other run-and-gun is quietly measured.
Context matters here. The original Metal Slug, which we have covered on this site along with its fascinating development story, was a triumph of focus: six missions, a war against General Morden’s army, a perfect arcade loop. Metal Slug 2 and its remixed sibling X added aliens, mummies and the series’ beloved slowdown-heavy chaos. By 2000, with SNK’s fortunes collapsing around them, the Metal Slug team faced a choice between making one more solid sequel or making the game that would have to stand as the series’ monument. They chose the monument.
Five Missions, a Dozen Games’ Worth of Ideas
On paper, Metal Slug 3 is shorter than you would expect — five missions. In practice, each mission is a small labyrinth. For the first time in the series, levels branch extensively: dive underwater in the opening mission and you will fight through a sunken route full of giant eels and enemy submarines; stay topside and the level plays completely differently. Mission 2 can route you through an ice cavern. Mission 4 splinters into a jungle path, a subterranean tomb and a vertical climb that plays like a tiny shoot-’em-up. A single playthrough shows you perhaps half the game, and the other half is not filler — it is some of the best material in the cartridge.
Then there is the famous zombie level. Mission 2 begins in a snowbound town where Morden’s forces and a risen undead population are having a very bad evening, and it contains the series’ most inspired transformation: get caught by a zombie’s attack and your soldier becomes one of the undead — slow, shambling, unable to use vehicles or most weapons, armed instead with a screen-clearing fountain of blood vomit that ranks among the most powerful attacks in the game. Find a health pack and you are human again; stay a zombie and you are a glass cannon with the funniest walk cycle in gaming. It is a joke, a mechanic and a genuine strategic choice all at once, which is Metal Slug in miniature.
Animation Density as a Design Philosophy
What truly separates Metal Slug 3 is the density of its craft. Every enemy in this game dies elaborately. Rebel soldiers do not simply fall; they flail, flee, get launched into the scenery, or pause to laugh at you before remembering they are in a war. Crab monsters, killer plants, man-eating fish, yeti, clone soldiers and the enormous boss constructs — a giant hermit crab wearing a wrecked battleship, a towering alien monolith, a UFO mothership — are each animated with a care that modern games, with a hundred times the budget, rarely match. Backgrounds are layered paintings that the action constantly vandalises: bridges collapse, walls crumble, entire ships sink under you mid-fight.
The menagerie of Slugs deserves its own paragraph. Alongside the classic tank you will ride a camel with a chaingun, an elephant, an ostrich, a drill tank for the underground routes, a submarine, an aircraft, and — in the astonishing final mission — a rocket into orbit and a space pod for the descent. The finale alone is nearly as long as some entire arcade games, a multi-stage assault that moves from launch pad to mothership interior to a desperate rearguard action, and it ends the Morden-versus-aliens storyline with genuine operatic excess. Playing it in one credit remains a legitimate badge of honour.
Hard, But Honest About It
None of this comes gently. Metal Slug 3 is a difficult game — the hardest of the original trilogy by most reckonings — and its final mission in particular was designed to harvest arcade credits. Bullet patterns thicken, enemies arrive from behind, and some of the later bosses are endurance tests. But the difficulty rarely feels cheap in the way lesser run-and-guns do: your hitbox is tiny, your knife is devastating at close range, and the game is constantly handing you heavy machine guns, rocket launchers and shotguns as if apologising in advance. Co-op play, as ever, transforms the experience — two players can revive each other’s momentum and share the blame for the zombie incident.
It is also worth noting how well the game has travelled. Metal Slug 3 has been ported to virtually everything, and the ACA Neo Geo and compilation versions are arcade-faithful, slowdown and all — and yes, the slowdown is part of the flavour, the original hardware audibly straining under the weight of its own ambition.
Metal Slug 3 is the series at maximum volume: the funniest, strangest, most generous and most demanding entry Nazca and SNK ever produced. If you play one run-and-gun on the Neo Geo, the original’s purity makes a strong case — but if you play the one that shows everything the hardware, the artists and the genre could do when nobody told them to stop, it is this one, every time.
Routes for the Returning Player
If you know Metal Slug 3 already, the branching structure is your invitation to treat it as several games in rotation. Take a run that commits entirely to the water routes and the underwater Slug, and the opening mission becomes a slow, tense submarine duel utterly unlike its topside sprint. Save your exploration of Mission 4’s tomb route for a co-op evening, when two players can split the screen’s dangers. And chase the score properly at least once: prisoners rescued in sequence, routes cleared without dying, and the end-of-mission bonuses for the truly obsessive turn this generous game into a stern one. The series’ scoring culture — huge, competitive, still active — begins in earnest here, with a game deep enough to sustain it.
A final word for the squeamish: yes, you can turn into a zombie, a mummy in spirit if not in name across the series, and at one point your soldier’s weight becomes a tactical concern after one transformation too many at the buffet of dropped food. Metal Slug 3’s comedy is not decoration on the action. It is the action’s reward — the game makes you laugh precisely where other run-and-guns would make you swear, and that generosity of spirit is as much a part of its greatness as any animation frame.
Our scores on this site try to leave room at the top for the games that define their systems, and Metal Slug 3’s nine reflects a single honest reservation: its difficulty in the final mission will wall some players out of its greatest material unless they feed it credits or a co-op partner. Everything else — the art, the invention, the sheer quantity of game — sits at the ceiling of what the Neo Geo ever achieved. A nine with an asterisk, then, and the asterisk reads: bring a friend, and it is a ten.
Score: 9.0/10