Rescued hostages are the greatest contributors of points. But you have to stay alive to get credit for your rescues (Once you complete a mission, you receive 10'000 pts for every POW).
MISSION 1, Deserts of Arabia : You are sent to control a loyalist force suspected of building weapons of mass destruction.
* The tallest tree after the 1st building contains lots of fruit and 3 hidden POW's.
* Palace : Shoot towards the right of the red banner to release 2nd lieutenant Hyakutaro Ichimonji. This mystic POW has an energy bolt which is powerful and homes in on anything you can shoot (this means structures as well; collateral damage). He'll help you until you finish the mission or die.
* You'll find the Camel Slug after the conversing Arabs. It comes equipped with a Vulcan but provides no cover against enemy fire. Like the Metal Slug, the Camel can run over enemy soldiers.
* BOSS 1, Harrier VTOL : Waves of swordsmen rush at you. Take them out before they get too close. After about 100 shots, 2 bazooka grunts open fire. Stay in between the jet exhausts. Aim for the engines as much as possible (You'll see and get 10,000 pt. for the 1st wing and 50,000 for the 2nd).
MISSION 2, Valley of the Pharaohs : Intelligence has indicated that the enemy army is using a secret Egyptian site to house military machinery.
* Use your gun to knock out an eye from the Sphinx (30,000 pts).
* Without hitting the explosive barrel, kill the Imperial Guards. Then, fire at the top right corner offscreen, for 3 POW's.
* If you stand next to the 1st and 3rd miners, they'll dig up some bonus items.
* Shoot at the top right of the support tower for a POW.
* Pyramid slope : A gem or 3 POW's are hidden at the top of the screen, right above the spot where the 1st mummy pops up.
* If you get a whiff of undead breath, you'll become a member of the undead, identifiable only by headgear. You'll be carrying only a pistol. Jumping is also quite a task. The flashing healing potions will turn you back into a human instantly.
* Near the door, get the POW's before clearing out the mummies.
* You'll catch up with Rumi Aikawa here. Shoot her for a healing potion or points.
* The eye hieroglyph before the special mummy hides a gem.
* Shoot the deceased explorer to make her give up a gem. Disgruntled, she'll give you the matching stick of dynamite.
* Jogging to the left, you'll see a few platforms to jump on. From the 2nd to the top, you can carefully jump over to the right. The long one holds 2 treasure chests. But don't stop here. Carefully jump on top of the cat statues. Shoot the chest open, which holds a magic lamp. If you are patient enough, a djinni will appear. Wait just a moment longer, and he'll grant a wish for riches. Starting from the moment the lamp is released, count the plumes of smoke and jump after the 5th one. Shoot above the right statue for another magic lamp.
* On the next level path (8th platform), the head of the hieroglyph holds gems. Shoot'em out!!
* If you let the mummy attack the explorer, you can destroy the new mummy for a gem.
* The twin-armed Slugnoid vehicle is located on one of the higher ledges of the tower of doom. The main cannon (C) fires downwards ((A)+(B) Swan Dive)
* BOSS 2, Iron Claw : Use your cannon and bombs. If you stay at the same altitude for a while, Iron Claw rears back and charges towards you. It won't fire while doing so, giving you time to get free hits in. When Iron Claw primes up, jump to the side ledges.
* BOSS 2 Freeze bug - Stop the nasty climbing! This original flaw give players an unfair advantage to eliminate Boss2 without any difficulty. Below is the following of how to activate. When the player standing on the platform which placed on the last chest, jump to the right edge of the next platform and fall to right lower platform immediately. The screen scrolls up and the boss emerges from the bottom of the screen. Instead of being killed as usual, the player is still there safe and sound ,while the boss freezes and do no climbing at all. At this moment, Just stay on the platform where you are and attack then it will be destroyed afterwards. The trick is also possible when riding the slugnoid or two players' game, but both player must do it at the same time.
MISSION 3, Supply Train : You've managed to catch up with an enemy train headed for a night shipment to the Far East.
* At the engine of the train, rescue the POW. Shoot at the smokestack from below to release 3 POW's.
* From the head of the engine, manage to clear more space with your jump to the next train for 50,000 pt.
* Use the Slug flyer which is equipped with a Vulcan that is limited in angular range.
* BOSS 3, Four Legger : While the boss is standing, jump to shoot at it. Everything except the flame-thrower can be avoided by hiding underneath its legs. If you still have the Slug flyer, stay on the left.
MISSION 4, Chinese City, Downtown : A platoon of enemy troops is stationed nearby.
* Collect as much of the food as you can. Once you're fat, your weapons will cause more damage but you'll be slower.
* Most of the buildings can be demolished, revealing hidden POW's or bonuses. Some of the POW's can be reached by knocking down the building they're on or the one next to it.
* Right about where the monkey and fish are, jump into an opening in the walkway and find POW's and a diet shake.
* Sitting on a rooftop of the residential area is your Metal Slug.
* BOSS 4, Big Tank (kind of battleship) : Only the cannons take damage during this battle. If using the Metal Slug, try for the lower cannons first. Use the houses and boulders to aim for the higher guns.
MISSION 5, New York : The townsfolk have been complaining about strange smells and sounds coming from the sewers. Intelligence confirms that a battalion is stationed inside, ready for an invasion.
* Jump on top of any of the cars, firing downwards. The car will burst in flames, sending you into the sky to reach a lot of bonus items.
* At the end of the street, shoot at the fire escape of the last building for 3 POW's and into the tree for fruits.
* At the underground railroad, shoot into the top of the arch for POW's.
* As soon as one of the 4 trains approaches from the right, fire immediately.
After destroying each one, run to the right to regain any lost ground.
* After marker zero (0), the track bends from here. But before you shoot at the EXIT door, fire at the ceiling. There are 3 separate spots with hostages.
* In the sewers, you see a box with an arrow on it. Find the lever and press (A) to wind it. After 3 turns, an item will drop down with a weapon or bonus.
* BOSS 5, Nuclear Submarine : Surfacing from the sewer slime, the sub attacks with a lot of lightning balls and a thunder cannon. When you see double barrels pop up, prepare for some serious thunder. Fire the Vulcan and bomb it at the same time.
MISSION 6, Siberian Shipyard : Far from Moscow, the rebel army has secretly established war factories and rebel headquarters.
* Mountainside : the sign with the arrow hides a POW.
* Midboss, Super Soldier : Fully recovered from his wounds of Metal Slug 1, he challenges you to another showdown. The horizontal shots can be ducked. Sometimes, you can knife him once and jump away. Take whatever shots you can in the meanwhile.
* In the submarine factory, after busting the tank, use the platform to release the hostage on the higher platform.
* Small platforms give you access to some of the prisoners on the top level, but it's easier to fight aliens on the lower platform.
* When the 2nd area is clear, turn the crank to release a Laser Rifle.
* 3 POW's are hanging at the top of the screen after the 3rd area.
* A POW is hidden on the short plank in the 4th area.
* BOSS 6, Battle Drone : Use the platform to the left whenever possible. When the rod is exposed, it will prime up for 2 seconds, then fire a bolt. Keep a constant fire when free from the Battle Pods.
* FINAL BOSS, Mothership : Fear not the various grunts and tanks, they are here to help you. Try using them for cover. Aiming upward from anywhere will hit some section of the ship. The soldiers bring in a Metal Slug later in the battle, just unload it from the truck. After a long and ruthless battle, the Mothership withdraws.