Venom, the final planet of the Lylat system. The biggest threat here is Andross, and despite being the final boss, he is actually very easy if you know exactly what to do. There are two different ways you can come about him, the first being coming from the easy path (Bolse). When you face Andross at this difficulty, you simply need to destroy him once, then destroy the second mechanical monkey head. If you come in from Area 6, you will have to destroy his first form and then his brain.
The Battle With Andross
When taking the easy route, you actually experience the whole level of Venom, with the inclusion of one boss before Andross. You will be greeted by swarms of enemies. After shooting as many of those as possible, you will have to fly through a valley, choosing between the left and right paths a couple of times. Some paths have obstacles to dodge and some have more enemies. All paths still lead to the same spot: two sets of horizontally rotating beams to avoid. The checkpoint is located at the end of the field. You probably need its shield refilling effects if you had trouble with the obstacle field.
You will now have to enter a tunnel and face a robot boss. Try to grab the Laser Upgrades. Shoot all of his armor (legs, arms, body, and head), then shoot him some more. Beams will emerge from the walls of the tunnel, so you will have to avoid them. You will also have to avoid the arms swatting at you from the sides. Once you've defeated this boss, the tunnel will end and you'll fly a volcano. Grab all three Gold Rings, both Laser Upgrades, and the bomb. Avoid the purple laser bars.
There is one universal technique that works for both routes when defeating Andross. In his first form, simply shoot at his eyes constantly until he goes to rub one of them. Take this opportunity to shoot at his hands as much as possible. When he finishes rubbing, simply repeat the process until both hands are destroyed. Then simply shoot his eyes to destroy him.
Andross will initially attack by firing a pink laser from his left forefinger. The laser will track you slowly, so fly to the top of the screen. If you take too long destroying his hands or destroy the left one, Andross will use a new attack. He will snatch at you and suck a bunch of rocks into his mouth. If you run into Andross, you will join the rocks, lose a wing, and return to single lasers. To prevent this, fly into a corner and barrel roll until he stops sucking. He will then chew the rocks for a few seconds and spit them out. Shoot constantly when he spits the rocks to prevent them from damaging you. Andross is invulnerable while he is chewing.
If you came from Bolse, keep shooting the eyes even when they start to blow up. If you've got Hyper Lasers, this will destroy the mechanical monkey head before it can attack you. Otherwise, just keep shooting it until it too blows up. The game will then be over since the CPU will fly you back out.
The Final Battle
Before facing Andross when coming from the hard path, you have to face Star Wolf. Their ships cannot be damaged with tracking lasers or bombs. After you finish off the Star Wolf team, you will descend into the volcano to reach Andross, activating a hidden checkpoint. There are many different paths you can take when entering, but the optimal path is LEFT, RIGHT, LEFT, LEFT, RIGHT, RIGHT. When you take that path, you should obtain 2 Laser Upgrades, a Smart Bomb, and three gold rings, everything you need to destroy Andross.
When you defeat Andross' first form, you will have to defeat his brain form in all-range mode. In order to damage the brain, you must destroy the eyes. If you somersault immediately upon entering all-range mode, you can throw a bomb just as the eyes are being released to destroy both of them. If you don't have any bombs or this technique doesn't work, you'll have to shoot them separately. The connections between the eyes and the brain can damage you.
After destroying his eyes, you simply have to destroy his brain. Its weak spot is the green back. Occasionally when you shoot him, he will teleport. It's a very predictable pattern. If he teleports, simply do a U-Turn, and he's right there. If you fly into him, he will downgrade your arwing the same way he would have if you got into his mouth. Once you finish him off, he says, "If I'm going down, I'm taking you with me!" After he says this, Fox will scream and the screen will go white, but then his father tells him never to give up.
Then comes the final part of the level, following James McCloud out of Andross' lair. This is slightly difficult, considering Fox's father is moving slightly faster, but you must follow James at all times. Boost frequently to avoid falling behind and dying. If you take a wrong turn, you will also die. If you took the optimal path in, the path out may be RIGHT, LEFT, RIGHT, RIGHT, LEFT, LEFT, but you should only use this if you lose sight of James. Thankfully, there is an automatic checkpoint after you defeat Andross, so you won't have to defeat him again if you die. Once you follow James out, the game is over. Congratulations! After the credits, you will be able to enter you initials and view your final score.
In order to obtain a medal from Venom, you must destroy 200 or more enemies, and keep all of your wing-men alive. It is fairly easy to get the points as long as you kill off the Star Wolf team quickly, which should get you a 50-Hit combo if you are fast enough. However, getting the whole team to Venom and through the first half is much harder.