- Required items: Communicator α (red)
Part 1
After landing by parachute on the lower left corner of the map, you must start out by getting over the barrel to your right. Since you can't jump, shoot your grappling hook at the ceiling over the barrel and swing across to the other side.
You will see a soldier above you. You can either climb up to attack him, or wait for him to drop down to you and shoot him as he falls. You have no health meter at this time, so contact with an enemy is immediately deadly. Soldiers always hesitate for a moment before dropping down. After he is defeated, he will leave a bullet behind. Be sure to collect these bullets whenever they appear, in order to increase your level of experience and build a health meter.
While climbing up to face the next soldier above, you must find portions of the platform that are not lined with barrels. While you can connect to any portion of a platform, you cannot pull yourself up to the top if barrels are in your way. Use the platforms around you to reach the next soldier, defeat him, and collect the bullet he leaves behind.
When the coast is clear, pull yourself up to the door marked with the A on the map. This is a communication room. Walk to the console, and the scene will switch to the transmitter screen, where you have two choices.
- Communicate: MA-1 tells you about the importance of communicating with your allies in order to get important information. It also causes new pathways to open, such as the door to the interior portion of this stage.
- Wiretapping: One soldier warns another about an elevator, referring to the elevators found in the interior portion of the stage.
Once you are done, head outside and drop to the location marked B on the map. Bear in mind that all previously defeated soldiers return when you exit a room. Stand near the edge of the platform, and firing your grappling hook at the lamppost. Then swing across to the platform on the opposite side. Then drop down to the ground level.
Walk to the right, and you will face a soldier with a large gun. He squats down until he's ready to fire, and takes several shots to defeat. Collect his bullet, and then climb up to the platform above. Another soldier will be hiding behind a barrel to the left. He will only be vulnerable to attack when he stands up. If you defeat him, he will fall down to the left, so you won't be able to collect the bullet he leaves behind.
Instead, head to the right. A door will open, and another gun soldier will step outside and squat behind the barrel. Shoot him when he stands up. Climb up to the location marked C, and stand on the platform above. You'll have to shoot your grappling hook at an angle to the platform above. Wait until the soldier there finishes firing, and then pull yourself up to the platform and shoot the soldier before he has a chance to attack.
Time your approach before the next two soldiers so that you pull yourself up right after they have fired their gun. You can collect the bullets they leave behind by firing your grappling hook straight ahead as the bullets bounce. Then climb up to the door marked D on the map, and step inside.
Part 2
From the entrance, step to the right to stand on the elevator at location E. There are three "floors" that you can ride the elevator down to. The first floor contains two dead-ends. The third floor allows you to explore the region to the left, but you likely won't be taking the elevator all the way down there because the second floor contains a communication room at F. After you leave the communication room, you will find that the elevator will have disappeared (in NES only). Note that if you take the elevator too far down, you will be impaled on the spikes at the bottom.
In the room at F, you will learn the following:
- Communicate: You can probably find a useful weapon in Area 4.
- Wiretapping: You will need flares if you intend to visit Area 4.
From the communication room, head to the left, and use your grappling hook to swing over the gaps. Once you are in the opposite hallway at location G, enemy soldiers will begin parachuting down to your level. A little ahead, you will see an energy barrier beyond a barrel. Grapple up to the ceiling and pull yourself up so that you can gun down the barrier generator. Then swing over the barrel to continue.
Once you are in the area with green platforms, enemies will appear constantly. By now you should have collected more than the 5 bullets to begin your health meter, and well on your way to 15, if not beyond. Most soldiers will float down by parachute, but some will appear from behind doors with guns or bazooka. They will only do this if there are not already three soldiers on the screen. Notice that the soldiers with bazooka may lob a grenade to you, as well as using their bazooka. These attacks deal same damage though.
Additionally, when you reach the green area, you should see your first item box floating down by parachute. This box may contain an extra-life, a health potion, a bullet, or a POW barrier. Grab it as long as it's safe to do so, but don't risk your life for it.
Your goal is to reach the door in the upper left corner at location H. The constant appearance of enemies can make it difficult to find a good time to climb up to higher platforms and advance, but do your best to clear away any threat before moving on. Eventually, you must grapple over to the ledge where door H is found. The low hanging ceiling can make that difficult, but you can swing over to the area just in front of it.
Before you head inside the door, this is a great opportunity to defeat the constantly appearing soldiers, and collect as many bullets as you have the patience to get. Just walk back and forth as the enemies appear. 60 is the recommended amount that you should try to collect before you enter the door. If you can hold out until 100 or 150, even better, but there will be more opportunities to get bullets throughout the game.
Boss
You will arrive in the room with the main computer for this stage. After walking to the right, the commander of the room will tell you that your efforts are useless, and then command the never-ending supply of soldiers to attack you. You don't need to focus on the commander. Just run underneath him, and head to the platform just before the machine. Grapple up and pull yourself up to it. Situate yourself on the left side where you are safe from falling soldiers, and shoot at the machine. It will take a steady stream of bullets for a few seconds before the machine blows up. Once it explodes, you will have successfully completed the stage.
Reward: You will earn ten bullets along with the Energy Recovery Pills (really a potion). To use it, select it from the item screen before a stage starts, and press 
. You can only use it once per stage.
Famicom Differences
- In Part 1, there are more soldiers that, Ladd can gain his first health extend before entering the communication room.
- There is a parachute box in the middle of Part 1.
- At the entrance of Part 2, there are two elevators. The wire-tapped info from Part 1 is referring to the left elevator, which is broken and will fall when you step on.
- There are no paratroopers in Part 2. Instead, there are more rocket soldiers coming from the doors.