The seventh stage begins the remaining sequence of horizontally scrolling stages which take place until the end of the game. While there are still three more stages after the seventh, there are no breaks between them, so they may feel like one continuous stage. This is the final rush into the enemy's headquarters. This stage occurs in a frozen tundra. Enemies will rush toward you immediately when the stage begins. Shoot at them as quickly as possible to destroy them before they shoot at you. Crouch if necessary to avoid their gunfire. From the trees in the background, grenades are tossed out in front of you. Both the grenade and the explosion it creates are dangerous to touch.
You can obtain a Spread gun from the weapon sensor in the cliff wall. This occurs just before the anti-gravity shuttle arrives, which resembles a UFO. Soldiers will pour out of it from every direction. They will jump out and land on the floor before running toward you, as well as fly out from the top hatch wearing jet packs. Bombs are also dropped from the central shaft, making it difficult, but not impossible, to pass directly beneath it. Begin shooting up and to the right as soon as you see it in an effort to damage it before enemies start to emerge from it. You may be able to destroy it before that occurs. If not, stand directly below the left edge of it and fire upward. With a good gun, you will be able to destroy any enemy that pops out of the left side, and continue to strike the shuttle when there's a break. Every now and then, you will have to stop and fire right to destroy any enemy that is advancing upon you from that side.
Once you pass the shuttle (note that you are not required to destroy it), a river will come into view along the background. Drop down the cliff, and watch out for the Gunners will appear along the path. You will have to crouch down and shoot them from a safe position in order to destroy them and get past them. However, you'll need to pay attention to the area behind you in case a soldier comes running up to you from behind. More scuba soldiers sit in the water, waiting to launch mortars into the air. However, they are positioned close to the ground, at a level that is easy for you to shoot and remove them before they can be a threat to you.
Climb up the next cliff when you reach it. If you do not have any weapons, two weapon capsules will appear from the left. The lower one will contain a Machine Gun. If you collect this before the other capsule appears, the upper capsule will not fly in. The upper capsule contains a Rapid fire upgrade. It is possible to collect and activate both, even though this is a combination that the game does not ordinarily allow. Doing so will allow you to shoot extremely fast machine gun bullets, and ensure your victory through the next phase. Once you're back up on the higher ledge, you will face not one, but two heavily armored vehicles back to back. They approach you and stop a certain distance away. The gun at the top tries to shoot at you, but it has very limited angles to fire at. You should be safe standing in the back, or crouching in front of the truck. You must shoot the truck enough times to destroy it or it will run you over. The trucks turn more and more red as you continue to damage them until they explode. This is next to impossible to accomplish if you have no special weapon equipped. If that is the case, all you can do is fire as rapidly as you can in hopes of destroying them before they reach you.
After destroying the vehicles, the snowy tundra ends, and a more industrial look begins. The eight stage starts out with a visit from a heavily armored giant who approaches you from the right. It will do one of two things; it will either jump up into the air, or it will toss discs at you. The discs cannot be destroyed and must be jumped over. You must shoot the giant until it is destroyed, while avoiding attacks from the discs. If you still possess the powered-up machine gun from the fight with the armored vehicles, you can destroy the giant before it gets to throw one disc, but you must jump with him in order to hit him enough.
The stage continues is you delve deeper into the energy center of the enemy headquarters. Tubes spread out in every direction, conducting energy to other parts of the base. There are portions of exposed tubes where fire blasts out at regular intervals. These blasts of flame must be avoided. In general, it is usually possible to avoid getting burned by crouching below horizontal flames. As a result of the flames, it is not a good idea to rush through here. Instead, proceed cautiously and get a feeling for the placement and timing of these flames so that you can get through the stage unharmed. Be aware that the small flames which indicate the presence of the blasts can not harm you.
Later on, the stage is divided into three floors. You are generally safest running along the top floor since enemies won't shoot upward at you. Lower levels feature Gunners and soldiers who throw grenades, although they are weak and easily defeated. Toward the end of this section is a weapon sensor in the middle which contains a Laser gun. If you don't have any weapons, a capsule will also fly on to the screen which also contains a Laser. It's a good idea to switch to this weapon, and the last chances for you to do so, as there no further weapons provided throughout the game.
As you exit this stage, you will encounter a second armored giant. Although it looks identical to the first one you encountered, this one is much stronger. Some of the discs it throws explode when they hit the floor. It may also leap forward and backward on occasion. The laser can make short work of this giant, but not before it can toss a number of discs at you. There is one trick which you can use to avoid getting hurt. Before the left edge of the ledge disappears off the screen, you can stop and run back to the bottom level when the giant appears. Shoot up and to the right while the giant leaps around, and you should be able to attack and defeat the giant, albeit more slowly, without the risk of getting hit by him or the discs.
The ninth stage is a hanger that is populated with a large number of soldiers. They will appear constantly throughout this stage, so you'll have to stay alert. In addition to the soldiers, there are spiky devices which hang from the ceiling and drop. Some move slowly while others move quickly, but they both move with a regular rhythm. You must proceed beneath these spikes without getting hit on the head. If you are forced to move below one while it is coming down, you can crouch to avoid getting hit, but you must stay there until the spikes retract to the ceiling. The upper path contains few soldiers but more spikes, and vice versa. If you have no special weapon in this stage, one more capsule will appear, and it is a Barrier item. Collecting this can aide you tremendously as it will allow you to run all the way through the stage without fear of getting killed, and keep you alive throughout the fight with the alien head coming up. If you have a weapon, or you miss the Barrier, you'll have to proceed with caution, especially when the mine carts appear. You can jump on top of the mine carts, and you can blow them up, but do not allow one of them to hit you or you will die. This stage ends with a Gunner stationed just after the background fades to black, so be prepared to squat.
Once you clear the hanger, the tenth and final stage begins. A purple organic background appear. You will now be taking on the alien lair that resides in the heart of the enemy territory. As you approach the first challenge, Floaters begin to fill the screen from seemingly every direction. Though difficult to clear, do your best to remove all of them before you advance to their source: a giant alien mouth that extends down from the ceiling. The mouth will continuously produce Floaters until it's destroyed. Just before the mouth is a pile of rubble which serves as a good stopping point for you because it positions you directly below and to the left of the mouth. From here, you can easily shoot up and to the right into the mouth and damage the mouth until it explodes. Any remaining Floaters will be eliminated when the mouth is defeated. If you arrived here with the barrier, you should have just enough time to destroy the mouth before you even have to worry about getting killed by Floaters.
After destroying the mouth, you must run through a corridor. On the floors and ceilings of the corridor are small faces which constantly spit out Spores. The Spores start out slow, and build up speed. They try to home in on you and collide with you, although they are not capable of turning rapidly in mid-air, so it's possible to outrun many of them. Nevertheless, you should continue to shoot your gun around you in an effort to reduce their number as much as possible. It is possible to destroy the faces and stop the Spores from appearing, but doing so causes you to stop and leave you vulnerable to attack, so don't attempt this unless you have a good weapon. Eventually, Crawlers will appear along the floor and ceiling, indicating that you are very close to the final boss.
At the very end of the stage, you will encounter a large beating heart which is heavily protected by six cocoons (three on the floor, and three in the ceiling) as well as a few faces that spew Spores. In order to complete the game, you must shoot the heart (which does not have any form of attack of its own) until it is destroyed. However, the cocoons and faces around the heart will produce a limitless stream of Crawlers and Spores in an attempt to stop you. Both the cocoons and faces can be shot and destroyed, but it will take a lot of firepower to remove them all. In the time it takes you to clear them all away, you could potentially destroy the heart instead, so you must choose your battle strategy carefully. Obviously, a weapon like the Spread gun will allow you to attack just about everything very quickly, but it's difficult to make it to this point in the game with the Spread gun in your possession. The heartbeat will increase as it takes more and more damage. If you succeed in defeating the heart, you will earn one million bonus points, and you will get to watch the developer credits before the game ends. Congratulations.