Two years following the events of Metal Slug 4, the Peregrine FalconStrike Force, the SPARROWS, and the Ikari Warriors are once again on a search for General Morden and his army, this time on a giant island landfill that has been converted into a military fortress, in order to stop his latest coup d'état. After having his newest weapon crushed by the heroes, Morden receives unexpected help when a time portal opens up and high-tech soldiers from the future appear to pledge their support. With their advanced technology, Morden is able to further fortify his base, but the heroes push forward despite the incredible odds. At the very end, the heroes are able to destroy the time portal and cut off the Rebel Army's suppliers. Morden escapes in a giant mechanical Kraken and confronts them over a lake of molten lava. After a long and arduous battle, Morden is defeated and his weapon begins to sink into the lava. The heroes capture Morden and escape via helicopter, but he escapes when the Martians attack the helicopter. The final scene shows the heroes chasing Morden and his men off into the sunset.
Gameplay
There are seven levels and three difficulties: Beginner, Normal and Hard. Metal Slug 7 uses the Nintendo DS touchscreen as a map of the level, making it easier for the player to look at the level and where to get power ups or captured prisoners. The usual weapons make their return from the series including a new weapon called "Thunder Shot", which fires a homing electric blast to the enemy. New to Metal Slug XX is downloadable content which includes the addition of Leona Heidern from The King of Fighters series as a playable character.
Characters
Similar to Metal Slug 6, each character has unique gameplay traits.
Marco Rossi - His default gun inflicts more damage than normal. He can also rapid fire his default gun without mashing the fire button, but this requires him to stand still.
Eri Kasamoto - She carries 20 grenades instead of 10 when she starts each life, and can throw them in multiple directions and further. Collecting grenades will increase them by 20 instead of 10.
Tarma Roving - He takes less damage when driving a Slug and can lock the Vulcan gun in a direction when firing for greater accuracy. In XX, he can also attempt to fix damaged Slugs by kicking them, though this doesn't always work.
Fiolina Germi - She gets 50% more ammunition for weapons and starts every life with a Heavy Machine Gun in her first weapon slot.
Ralf Jones - His swift melee attack can damage artillery and he can use his Vulcan Punch to rapidly destroy most enemies, but he only gets half the normal ammunition for weapons and grenades. He can survive a single hit, but will die after a second hit. Collecting grenades will increase his grenade supply by 5 instead of 10.
Clark Still - He can use the Super Argentine Backbreaker, a grabbing attack that can throw enemy infantry and also renders him invincible when performing it. Chaining multiple grabs awards greater points each time.
Leona Heidern - She gets slightly-increased ammunition for weapons and grenades and extra durability when in Slugs, and can use a special Moon Slasher attack that can damage artillery and block projectiles.
New slugs
The three new vehicles are:
Slug Truck: A road train-like machine that works similar to the Metal Slug, except that a cannon must be connected to the unit to access its secondary weapon. You can have up to four cannons connected, and they have unlimited ammo, but they are destroyed with a single shot.
Slug Gigant: The Slug Gigant is a giant robot that is capable of massive firepower. Pressing the secondary fire button fires its wave cannon, which neutralizes enemy fire, and throws a punch with its claws. Aiming its gun all the way down causes it to claw enemies on the ground. However, its primary weapon is the standard Vulcan. It has more health than most slugs, and if it is destroyed, the player loses a life and respawns in a new Slug Gigant. Because of this invincibility, it will survive to fight the boss of the level it is in.
Slug Armor: Has both vulcan and cannon. Can slide at high speed by holding D-pad down and a direction. Referred to in the manual as the Slug Gunner.
Soundtrack
The music in the game was composed by Toshikazu Tanaka, following on from his work on Metal Slug 4, Metal Slug 5, and Metal Slug 3D.
Reception
Metal Slug 7 received mixed to positive reviews. GameZone's Steven Hopper gave the PSP version a 7 out of 10, saying "If you are a hardcore Metal Slug fan then this is a good portable fix. It controls well and offers up plenty of action. The campaign is super-short, but this is a game that is meant to be played over and over again. Just don’t expect much in the way of innovation."
