Super Thunder Blade/Stage 4

Stage
Stage 4 is similar to Stage 1, though it takes place at night and the player moves at a slightly faster pace than before. In addition, the flight path now has horizontal barriers across them that need to be flown over, under or through a gap between two. The difficulty returns to the level of Stage 2, where you are forced to trade off between the safety of moving constantly through the air to avoid getting shot, and the need to slow down and maintain a position on the screen that will help you avoid colliding with the barriers.

You'll need to apply your air brakes quite frequently in order to ensure that you're properly lined up to avoid hitting the barriers. If you do find that you need to slow down, try to clear the space of any enemy fire before you attempt to proceed. It's not uncommon to be surprised by bullets that you couldn't see on the other side of the pipes.

During the first half of the stage, the barriers appear at a fairly consistent pace, and you'll never see more than two of them at a time. After the battle against the mid-boss, several barriers will appear more frequently, and there are occasions when you will see three barriers at once.

Mid-boss
Sigma-01 Sub-Commander (S-01) and Sigma-02 Sub-Commander (S-02) in western manual or SIGMA-01 [Σ-01] and SIGMA-02 [Σ-02] in japanese manual. Exclusive to Super Thunder Blade. 25 feet of mechanical armor for infantry, aka mechs. Sigma-01 will stand and shoot at you from a single spot while Sigma-02 hovers around and shoots as well, the latter usually taking longer to defeat. It seems as though your heat-seeking missiles have no effect on other enemy, so you'll need to rely on your Gatling Gun to destroy them. It is advised to concentrate on moving around constantly to dodge their attacks versus an outright assault.

Boss
Simply called Guerilla Basement in western manual. Exclusive to Super Thunder Blade. A top-down perspective boss zone that replaces behind-the-view perspective guerilla base boss fight in Thunder Blade. The only top-down perspective boss where it's mandatory to destroy a certain target.

This boss has guns scattered across the entire surface, including moving guns on rails, so there's no particularly safe location to be. You should continuously fly back and forth to avoid getting shot. Avoid using the air brake at all until you get to the very top of the ship. At this point, you should make every effort to destroy the four guns on either side of base, and then focus your attack on the main gun shooting several rounds at you in the center.

Once you destroy it, the panel beneath the gun will explode, revealing the true target of the base. It is a central gun surrounded by 12 smaller guns, three below, three above, and three to either side. You'll have to destroy all of them. Focus on the small guns around the center gun. Use the air brake to fly backwards a bit so that you can target all of them. Then focus your attack on the center gun. It opens and closes, and is only vulnerable when it's open. The core starts out green, and goes from yellow to orange to red as it gets closer to being destroyed. Once it explodes, you'll be treated to the end credits of the game.