Created in 1996 by SNK, the Metal Slug series would take a further seven years before surfacing in Europe (with Metal Slug X sneaking in during the twilight years of the PSOne), but it quickly started winning over gamers with its old-skool sensibilities. A 2D shoot 'em up with an endearingly mad-cap sense of humour, it captured the imagination with its detailed, cartoon graphics, uncomplicated run 'n' gun gameplay and a very obvious retro leaning - something it sported with obvious pride. It stood out; not afraid to be different. Thus it's rather sad that Metal Slug XX seems to embody much of what the original game stood against.
It's not a lack of modernising that hurts the series seventh instalment - after all, the fact it sticks two fingers up at 3D and HD makes it what is - it's more that the series seems to be caught in its own self-contained bubble; never improving, never offering anything different. It's deflating to see the same weapons, sprites, enemies and vehicles being wheeled out for the umpteenth time, meaning MSXX has almost no originality or individuality to speak of. So homogenised have the games become, that it feels little more than a mission-pack to Metal Slug 6.
The core gameplay remains unchanged, so what you get is a solid, uncomplicated blaster with a plentiful supply of incompetent foot-soldiers to mow down in the early phases before being assaulted by a barrage of armoured vehicles, helicopters, planes and missile defences. The seven missions encourage the player to rack up high-scores; free hippie-type POWs from faux-Nazi types and tackle bewilderingly huge, armed-to-the-teeth bosses.
As alluded to, improvements (and indeed changes of any kind) are very thin on the ground, but it does at least retain the six selectable characters carried over from Metal Slug 6, some of which offer more than cosmetic differences. Ralf holds the distinct advantage of being able to sustain a hit without losing a life, whilst Fio spawns with a machine-gun rather than the standard pistol. Elsewhere, you can carry two weapons, interchangeable with the shoulder buttons, meaning you can flick between the rocket launcher (or "Rocket Lawn-Chair!" as the voice-over appears to proclaim) and cult-classics such as the Iron Lizard.
It may all be very familiar, but MSXX does play soundly enough. The PSP offers responsive navigation for the characters, whilst the uncomplicated control system suits the format nicely, and the widescreen nature of the handheld is put to good use. The ability to select individual, previously-completed missions saves having to play start-to-finish each time, which is good common-sense thinking. There are unlimited continues, which is just as well, as you'll die hundreds of cheap deaths along the way, as enemies simultaneously attack from all manner of awkward angles, and too often death seems an inevitability.
I can't remember Metal Slug ever feeling so flat humour-wise. In the series hey-day, it thrived on odd-ball spontaneity; what other games allowed you to pick up pigs and vegetables as points bonuses, or ride a camel with mounted guns, or even feature a boss being devoured completely out of the blue by a giant whale? The quirky collectibles (pigs included) remain but feel nothing more than a hollow obligation. It's like a stuck record; seeing a rescued POW follow you and perform mock beat 'em up style fireball attacks on enemies was a good laugh the first couple of times, but seeing the exact same sprite pull the exact same gag all over again is just depressing.
It's colourful, bubbly and pleasantly retro to look at, but it's hard to commend the game's visuals given just how much of it is a cut 'n' paste job. Character animations and the vast majority of enemies and POW sprites are plucked from the earlier games, while the new level backgrounds are adequate but largely forgettable. Ditto the music and similarly-cloned sound effects.
The one area that sees Metal Slug XX rise from its copy-cat slumber is in its excellent end of level bosses. Typically epic in scale, you'll face seven David versus Goliath struggles with screen-filling metallic contraptions of death. It doesn't take long to get into gear either; the first level sees you battling a giant metal worm that burrows around your character, and a couple of levels later you're pitted against two fire-spewing machines simultaneously. For the most part, it's tempting to criticise the lack of new vehicles, but the penultimate level sees you pilot a mech so it big it fills nigh-on half the screen, whilst the last boss is well-designed and similarly grand in stature.
Depending on which of the three difficulty settings you play the game on, MSXX will take between 35 minutes and an hour to polish off. There are quite a few additional mini-missions to undertake in the "Combat School", though these mostly-derivative challenges are in truth a bit of a disappointment. Generally, you're tasked with retracing the main levels with limited lives or weaponry, or tasked with defeating the end of level bosses with similar such restrictions. There is the odd bright spot - trying to keep a half dozen beachballs off the ground for as long as possible by shooting them skywards with a handgun is a strangely compelling exercise, but such quirky distractions are few and far between, and there isn't much of any lingering interest.
Thus beyond a few run-throughs of the main game and a fleeting go in the Combat School, there isn't much mileage for your money. Especially if you consider that Metal Slug Anthology, which contains the previous six games (all of which individually better than XX) is available for roughly the same price. Metal Slug XX remains a solid title but sets its ambitions far too low. It's like a veteran comedian in need of some new material; Metal Slug seems content to retrace the same gags using the same props, caught in a perpetual cycle reminiscing about its pioneering days, and getting gradually less funny with each instalment.