Continuing with the theme of blowing up door panels, the entire opening section of this stage requires that you destroy not one, but two door panels to open each gate. One panel is on the floor while the other panel is higher up. While the floor panels are generally easy to destroy, you should take your time clearing away any threat before positioning yourself to destroy the upper door panel. Throughout this section, items will float down on parachutes. They typically pass beyond the gates before you can open them, and they are only there to make you rush and make a mistake. None of the items in the boxes are worth dying for, not even the high-point medals.
Very early on in this stage, a red gun will come floating down. This gun can make short work of the tall flame-throwing soldiers. The flame throwers run back and forth until they feel they are close enough to burn you. Then they let loose with their fiery attack. They may shoot while standing, in which case you don't even need to duck. But if they fire while they are squatting, get out of the way as quickly as you can.
Once you are all the way through the gates, you will step on a blue platform. Once you are fully aboard, the platform will begin to rise up an incline. During this time, a helicopter will fly on to the screen and hover back and forth above your head. The pilot will pause occasionally and prepare to drop a grenade on you. Fortunately, the grenade will pass through the platform instead of explode, but you must still stand out of the way of the bomb.
You're usually safest standing on the far right side of the platform. However, the helicopter may decide to swoop down and attack you. If this happens, run to the opposite side of the platform and prepare to pelt the helicopter with shots as quickly as you can. You may succeed in destroying the helicopter, but it will be quickly replaced with another helicopter. As soon as you reach the top of the ride, the helicopter will leave, but many more will appear.
The next section is a long sequence of platforms and ledges built along various columns. There will be an out and out attack against you, featuring soldiers, short soldiers, flame-thrower soldiers, helicopter, and mech pilots. In general, your goal should be to continue moving upward and to the right, although at certain points, you are limited by how far to the right you can go. Always make sure that the level above you clear before climbing up and finding another point to latch on to.
The biggest nuisance throughout this section is the helicopters. The mech pilots can be kind of difficult, but you can actually lose them because they can't climb or drop as fast. The helicopters have a much greater ability to stay close to you as you move throughout the base. It's important to time your climbs up to higher levels between bombings. If a helicopter is hovering fairly low and making it difficult to advance, try moving down a bit to see if you can encourage the helicopter to move as well. Just be careful that you don't drop down in an area with no floor below you.
When you reach the end of this section, you will have to climb a wide column with a narrow set of ledges to grapple up to. After passing a series of these, the background will change, and you will be in a long area with more enemies running along the platforms. Be especially careful around the flame throwers, but also watch out for any short soldiers that hop out of mech pilots.
Just above this final section, you will see two captains along with one commander running along near the exit sign. In addition, a flame-thrower soldiers and a helicopter will be nearby to make matters more difficult. Like the previous stage, you only need to defeat the captains and the commander in order to complete the stage. Any remaining enemy is irrelevant. Of course, it may make matters easier to remove them first before you concentrate on completing the stage. Once again, squatting down while you shoot can keep you safe from return fire.