5. Aliens vs. Predator Alien Campaign Walkthrough

There are two difficulty specific achievements, one for completing the campaign on Hard, and one for completing the campaign on Nightmare. These achievements are stackable. There are also a number of royal jelly containers hidden across each level for a collectible achievement. You have to destroy these rather than collect them. There is also an additional collectible achievement requiring you to harvest all civilians in the game. (Note that completing this campaign on any difficulty will count towards the Game Over, Man! achievement).

Game Over, Man!

Complete all three Campaigns

Game Over, Man!
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Magnificent, Isn't It?

Complete Alien Campaign on Nightmare difficulty setting

Magnificent, Isn't It?
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I Admire its Purity

Complete Alien Campaign on Hard difficulty setting

I Admire its Purity
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Quite A Specimen

Destroy all 50 Royal Jelly Containers

Quite A Specimen
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Level One: Research Lab

Come to Mama

Liberate the Matriarch

Come to Mama
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Breaking Quarantine

Escape from the Research Lab

Breaking Quarantine
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You begin this level in captivity. Fortunately, your captors decide to give you a brief tutorial on how to be an alien. This is definitely the easiest of the three campaigns, but also the shortest. It also the most stealth-focused as you only have melee options, and you aren't as durable as the predator. Fortunately, the marines are still as stupid as pig shit. You also regenerate health automatically instead of having to rely on stims or health shards, which is an added bonus.

You also have decidedly more options in terms of manoeuvrability. You can climb walls and ceilings, and you can blend into the darkness. You can also distract marines not too differently from the way the predator does. Anyway, after looking in the directions indicated by Doctor Groves, he'll walk out, and you will be released from your restraints. You will be instructed on how to climb walls, etc.

After dicking around for a bit, you will be provided with live prey. How considerate of them! After dispatching the target, you will be told how to use your tail to take things out. Use cn_LB to destroy the lights in the room. They will then send in another unfortunate victim. Dispatch them, and they will send an armed target. You now have the ability to lure enemies to a location by hissing, and you will have the ability to take down enemies by pressing and holding cn_X, much like the predator.

Once this is done, a cutscene showing the matriarch will play. You must escape! Anyway, go through the door the human suckers used, and there will be a vent on the ceiling. Jump onto the ceiling by holding cn_LT, looking up and pressing cn_A. To use vents, press and hold cn_LT whilst near, and press cn_A to enter. This is another advantage of being an alien, which is access to spaces where enemies can't get you. Anyway, as you approach the vent ahead, you will be trapped and gassed. Curses! You would have gotten away with it too, if it hadn't been for those pesky, meddling humans!

When you regain consciousness, you are back in restraints. Fortunately, a power outage will occur, freeing you from your restraints. You can kill the scientist if you wish. There are no harvestable civilians in this level, so go nuts. Anyway, exit the room through the door, and you will be able to escape via the vent on the ceiling. If you follow the first vent around, you will come across the first royal jelly container. Destroy it with your tail by pressing cn_LB.

You are now tasked with freeing your siblings. Continue past the jelly container, and exit through the vent ahead. There will be a computer in this room, which you can destroy by pressing and holding cn_X. Doing so will free your alien brethren. The second royal jelly container will be next to the nearest alien restrainer from the computer. Two security guards will enter the room, but they are no match for you. Feel perfectly free to crack open their skulls like Cadbury's Creme Eggs.

Exit the room, and turn right. Continue to the end of the corridor, and turn left. The third royal jelly container will be there. From there, turn around, and continue following the corridor around. Turn left at the corner ahead, follow the corridor, but stop before turning the corner. There will be a sentry turret around the corner, so you will need to do some wall climbing to get past it.

Look to your left, and you will see an upper walkway you can gain access to, either by jumping or wall climbing. Drop down onto the ground once you have reached the higher level, and you will find the fourth royal jelly container. From there, follow the walkway until you are past the sentry turret. Drop down, and the fifth royal jelly container will be behind it. The sixth will be literally right to next to it, except on the other side of the pillar right across from the sentry turret.

Facing the back of the sentry turret, turn left, and take the left corner ahead. You should see another balcony to your left with a marker indicating an air vent. Climb or jump up, and you will find the seventh royal jelly container to the right of the vent. Enter the vent, and follow it along. Exit the vent ahead, and take out the security guard here. You will find the eighth royal jelly container to the far right of the room.

From there, turn around, and go to the opposite side of the room. The ninth royal jelly container will be to the left, and a power node you must destroy by pressing and holding cn_X will be on the right. Destroying the power node will open the elevator door ahead of you. Go inside, and jump up to the gap above. Turn right as you enter the next room to find the tenth and final royal jelly container of the level.

From here, turn left. There will be two security guards here whom you can dispatch with ease. Once done, head all the way to the other end of the room, and there will be a computer on the right. Destroy it by pressing and holding cn_X, and this will free the matriarch netting you the 'Come to Mama' achievement. After the cutscene, the door behind you will open, and you will now have combat androids to deal with.

Of course, your alien sisters will join you and take them out. Continue into the next room, and follow it around until you come to a terminal you can destroy. Do so by pressing and holding cn_X, and this will gain you your freedom, thereby also netting you the 'Breaking Quarantine' achievement. This is the end of the first mission in the alien campaign.

Level Two: Colony

Grunt Hunt

Wipe out all of the Marines in the Colony

Grunt Hunt
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There are three harvestable civilians in this level. You also must kill every marine in the level for the 'Grunt Hunt' achievement, meaning thrice the collectibles. Anyway, when the mission begins, you will see a vent with a spinning blade fan in front of you. Just beyond it, however, you will find a vent you can access. Enter the vent, and take the path to the right. Exit through the first vent you come across. Once on the ground, turn around, and follow the sewer path. You will see a highlighted power node on the left ahead.

Destroy it by using cn_LB, and this will deactivate the blade fan above. This will also attract the attention of a marine. Climb up through the fan, and lie in wait. When the time is right, it's head-cracking time. There will be another marine back down the corridor. If he notices your takedown of the other marine, then simply back up through the grate again. Otherwise, he will most likely see you. Simply creep along the ceiling, and you can stealth kill him easily enough.

Continue on in the direction the marines came from, and you will come to a grate. There will, however, be a vent above that you can access to continue. There will be two marines in the area ahead. Both are armed with flamethrowers, and it can be quite hard to separate the two. It is essential that you DON'T take them on head-on as you WILL be cooked to perfection.

You will need to stalk them patiently. Anyway, once you have taken them out, return to the first vent you exited through in order to gain access to the area with the two flamethrower-wielding marines. Don't actually go back up there, through. From there, you will want to head down either one of the two tunnels ahead of you (it doesn't matter which). Once you have reached the end of either tunnel, stop.

From there, look up, and walk until you see the next vent you can access. Enter the vent, and turn around. Keep going, and you will find the first royal jelly container. Exit through the same vent, and continue along the path until the next vent you can access. Enter that vent, and continue forward to the next vent. As you should be able to see, there will be three marines ahead. There will also be a harvestable civilian.

Exit the vent. You will have to stalk your prey here, utilising stealth and patience. Wait until one is alone before striking. Rinse and repeat. All you need to do is creep up on them from above, and you can one-shot them using stealth attacks. The civilian, however, you can just harvest without sneaking up on, although I prefer to be sneaky.

Wait for the civilian to walk off, and wait for moments when a marine is isolated. Take each one out in turn. Once the marines are dead, there will be a power breaker in this room. Break it by using cn_LB, and the civilian will wander all the way back over to you. Once the marines are dead and the civilian harvested, drop down to the ground. You will want to look for a sign that says 'Pump Room.'

Facing the sign, turn around, and you will find the second royal jelly container. Turn back around, and continue down the corridor past the 'Pump Room' sign. There will be one more marine down here and another power breaker to destroy. If you try to scale the ceiling, be aware that there is a giant fan that can kill you instantly if you walk into it. Ask me how I know.

Anyway, kill the marine and destroy the power breaker using cn_LB. Now, facing the circular room from the direction you entered, turn right, and there will be a small alcove. You should see the third royal jelly container on the floor. With the power breaker destroyed, you should be able to climb into the giant fan above without being sliced into pieces. Climb up the ventilation shaft, and access the vent at the top.

Once through, continue forward, and take a right down the slope. You should find the fourth royal jelly container at the bottom. Turn back around, head back up the slope, and continue up through the hole into the next section of vent. You have now successfully escaped the sewers. Now, there will be a marine and a harvestable civilian in this area. However, the civilian will commit suicide if he sees you, so you will need to take a more careful and considered approach.

Continue forward and turn left. You should see a power breaker ahead of you. Destroy it by using cn_LB. The marine will wander off to "investigate." Continue past, and exit through the vent. The civilian dude should run off and seal himself in a room. It is imperative that you DO NOT try and force your way into the room, or he WILL shoot himself, which will void the 'Grim Reaper' achievement.

Crack open the marine's skull. From the room you entered, go through the door into the corridor, follow it around, and you should find the fifth royal jelly container. Return back to the door leading to the room the marine and civilian were originally in. Instead of going through it, look for a vent which should be to the right of the door. Enter the vent, and take a left. You will now be able to enter the room the civilian is hiding in through the vent there. Do so, albeit stealthily, and harvest the civilian. The culling is at hand! The humans' screams will be the overture to your symphony!

You will also find the sixth royal jelly container here. It is kind of hard to describe where it is. It is next to a shelf of items at the far end of the room directly opposite the main door. It is to the left of the vent leading in and around a corner in a little niche. After finding it, you can simply break through the door to the next room. Find the right one, and it will prompt you to press and hold cn_X. You'll headbutt your way in like some kind of Vin Diesel on steroids.

You will find the seventh royal jelly container in this room. Now, exit into the corridor and turn left. Climb over the debris underneath the vent and turn right. In this little section, make another right, and you should see an open elevator shaft ahead. Enter it, and drop down. You will find the eighth royal jelly container down here. Instead of climbing back through the open door, climb all the way to the top of the shaft, and you will find a vent.

Enter the vent, and you will emerge into the garage. There will be five marines and a harvestable civilian in this area that you are tasked with killing and harvesting respectively anyway. Here, there will be a bunch of lights on the ceiling that you may wish to destroy to make things easier. There will be sentry turrets in here, so be careful. Those things WILL wreck you if you get in their line of sights. Carefully stalk each marine, and take them out when they are alone. Simple.

Once the marines are dead, harvest the civilian, and you will be given the new objective of heading to the refinery. The last two royal jelly containers will be in this room, however. One will be on a desk in one of the corners of the room. The other will be in a motor pool with a truck above. Once you have destroyed the containers, head to the large marked door. This is the end of the second mission for the alien campaign.

Level Three: Refinery

There are a total of eight harvestable civilians in this level. Two will be in the corridor you start in. Harvest them, and continue down to the end of the corridor. Turn left. Headbutt the door open by pressing and holding cn_X. Continue through the corridor until you come to a right turning. Look above, and there will be a vent you can access. Enter the vent, and exit out of the vent the other end into the room beyond.

There will be five marines and two harvestable civilians here. Two marines will be on a raised catwalk. The other three marines will be on the level below with the civilians. I recommend taking out the guys on the catwalk first. Be careful as it can be hard to get at these two guys without being seen. Wait until they are far away from each other, drop down behind them, and stealth kill them.

I recommend staying above where you know they will walk to rather than following them, since the marines might hear you and become more alert. The guys on the ground can be tricky too as the ceiling is too high for you to crack open their skulls directly from the ceiling. You will need to risk climbing down the walls or simply jumping down nearby and sneaking out. One of them has a shotgun too and can one-shot you on Nightmare difficulty.

This part is annoying, because it is easy to feel confident after bumping off all the other marines, only to get noticed and one-shot by the final marine as you are moving in for the kill. Once the marines are dead and the civilians harvested, you can now look for royal jelly containers! Of course, after having had to move around to take out the humans, it will be difficult to establish a proper frame of reference once more.

Find the catwalk/walkway and climb onto it. Now, look at one of the walls the walkway joins onto. It does not matter which side. There is a number 9 on both walls. Except one will be on your left, and one will be on your right. This will be our point of reference. Okay, so the way the walkway is positioned, there is a narrow section of wall on one side of it. This will be to the left if the '9' is on the right, and to the right if the '9' is on the left. Anyway, halfway along there will be a pile of rubbish. On top will be the first royal jelly container.

Now, move to the end of the walkway where the number 9 on the wall ahead of you is on the right. Underneath the walkway, right under the locked door, will be a shelf of some kind laden with various crap. However, the second royal jelly container will be here. The larger side of the room should be on your right. Continue to the wall on the right side. The third royal jelly container will be halfway down the wall next to one of the power generators.

Continue following the wall until you reach another door you can headbutt open. Now, there will be two civilians in the area on the other side, and one will run off. This is counter-intuitive, but it is imperative that you DO NOT harvest him right away. Instead, run past him, and get the second bloke in the room beyond. The reason for this is because the first guy will call two marines who will come up in an elevator, but if you get the guy before he calls the marines, the second guy will escape, voiding the 'Grim Reaper' achievement.

So, chase the first guy down the corridor, and he will lead you right to his unfortunate mate. Harvest the second guy, and be ready to deal with the two marines who will come calling. Take out the marines, and you can harvest the first guy without incident. Before continuing down the corridor, the second guy tried to run down. Return back down the corridor you came from, and the fourth royal jelly container will be to the left of the door you entered to get to this corridor.

Return back to the room you bumped off the marines, and the fifth royal jelly container will be on the raised platform in the middle with the truck on it. The sixth royal jelly container will be on top of a shelf that will be to the left of the corridor the second civilian tried to escape down. Continue down the corridor the second guy tried to escape down, and turn to the right as you enter the control room. You will find the seventh royal jelly container here.

Now, in the left corner of the room will be a vent slightly obscured by some boxes. Knock them down and enter. At the end, you will see a large ventilation shaft with a powerful air current. DO NOT enter, or you WILL be sliced to perfection. Instead, hold cn_LT, and you will need to jump across to a vent. You will be able to jump back and forth between vents in order to traverse the ventilation shaft.

Once at the bottom, be aware that there will be two sentry turrets facing you down one end of the corridor. This is obviously not the way to go. Face away from the two turrets, and go down the corridor. There will be a power breaker on the right you can destroy if you wish. There will be a sentry turret to your left, however, but you can evade it easily enough. There will be another tunnel to the left past the one with the sentry turret.

Now, there will be a harvestable civilian in this area, so nab him before taking the corridor. Note that the eighth royal jelly container will be on the right side of said corridor. Don't forget to nab it once the marines are dealt with. The final harvestable civilian is down this corridor, but there are four marines to deal with. Be warned, because these marines are not quite as stupid as the others. There is high visibility and lighting, and at least two of them travel as a pair.

I have found that you will most likely need to lure them out by hissing to a darker section of the corridor, becuase it gets too bright farther in to take them out without them spotting you. Anyway, continue down the corridor once they are dead until you come to a split turn. On the left should be the sentry turret. You will need to take the right. The final harvestable civilian will be down here along with another marine.

You should also find the ninth royal jelly container as you come to a bend in the corner. Continue until you see a highlighted power breaker to your right. The tenth and final royal jelly container for this level will be ahead and to the left behind a rock. Go back and destroy the power breaker using cn_LB. Go through the large door that opens. This is the end of the third mission for the alien campaign.

Level Four: Jungle

You begin this mission up a tree, so begin by dropping down to the ground. There are four harvestable civilians in this level. Anyway, when you are on the ground, look to the right of the big metal doors, and there is a vent you can enter. As you enter, a facehugger will zoom off and take down one of the marines inside the compound. This should hopefully bring one of the other two over. Exit the vent ahead, and take them out.

From there, turn right, and you should see two rooms. The second marine should come through the room on the left. Anyway, there will be two sentry turrets blocking your path forward. There is one facing towards the exit of the room on the left, and one facing the opposite direction, meaning you can't go around that way. Instead, you will have to climb up to the level above, then climb the ruined wall, and jump down in between them.

From there, you can destroy the control laptop by pressing and holding cn_X. Once that is done, continue past them to the wall opposite, and destroy the power breaker. Enter the vent next to it and turn left. Follow the shaft all the way around, and you will find the first royal jelly container of the level. Turn back around, and continue all the way back to the vent leading outside into the swamp.

From there, head straight forward until you reach the cliff face. Look up and to the right, and you will see a raised ledge. There is a marine here, but also the second royal jelly container. Once both are dealt with, climb back down into the swamp. Now, the antenna you need to take out is through the tunnel to the right of jelly container, but there is a sentry turret covering the way up from there.

So, on the ground, head right along the cliff face, and look for somewhere to climb up discreetly without attracting the attention of the two marines. From the direction you are travelling, the antenna is to the left of the building. So, from the spot you climb up, head around the back of the building. Of course, it depends on where the marines are. If they are too close to the edge, wait for them to leave. Make sure you take them out, though, as this is required for a mission objective.

Once they are out of the way, THEN climb up around the back of the building. Climb on top of the building to get a good glimpse of the marines. You will most likely have to take them out to continue. Be warned as one has a shotgun and can royally screw you in all the wrong ways, even by alien standards. When you are convinced that the coast is clear, climb the antenna, and take out the power breaker on it by using cn_LB.

Jump back down, head back around the back of the building, and jump across to the cylindrical tower like structure. There is a small building nearby that has a civilian inside. However, he will flee and bugger off with a marine. A second civilian will be banging on the door as you approach and will also run away. Anyway, the third royal jelly container will be inside. Wait until the marines who enter leave before entering. Once that is done, exit the building.

You will probably have to hunt down where the civilians ran off to. I found one on the other side of the swamp. The other guy either runs off behind the building or the path to the next area. Alternatively, you can nab the first guy before taking out the antenna power breaker. Since you are tasked with wiping out all of the marines in this area, you will have to deal with any left alive. There should be three marines in the swamp, but they will head to the compound at the beginning of the level. I entered through the vents and used hissing and hiding on the ceiling to take them out one by one. Once they are dead, head back to the building that had the jelly container inside.

From the doorway of said building, facing away from the building, head directly forward, and you should come to the gap in the cliff wall. Follow the path, and you will come to a metal door to the left. I also found the second harvestable civilian along the path on the way to the door. Anyway, go through the door, and enter the compound. Be aware that there are predator proximity mines on top of some of the buildings. From where you are, turn left. Follow the wall around the corner, and turn left. Continue past the yellow construction vehicle, and turn left.

Go all the way down, and you should find the fourth royal jelly container there. Now, the little area this container is located in should be underneath a tall concrete structure. Climb to the top, and face left once you have reached the top. Look over the edge, and you should see the fifth royal jelly container on a wall below. From here, you will want to go back down to the ground.

The vent you need to access is north from where you entered the compound, past the yellow construction vehicle, in between the two outbuildings. Enter the vent, and immediately turn around. You will find the sixth royal jelly container here. Exit the vent again, and you will want to head to the right side of the compound (facing away from the direction you entered the compound).

There will be a power generator in the top-right corner. There will be a vent just before it. Enter it, and continue all the way forward. Turn right, and you should see the seventh royal jelly container in front of a grate. Return back to the vent you entered, and leave through it. You will want to find the building with the civilian inside. If you return to the vent just past the yellow vehicle, then you can follow the drain and enter the building through a vent that comes out through the floor.

Enter the building, and harvest the civilian. You will now have to get into one of the other two outbuildings. It is the one with the marine inside, and it should be marked on your HUD when you look at it. Enter, and the marine will flee, locking you inside. You can't kill the marine, since this part is scripted. You will now have to escape. There is an explosive canister in this room. Attack it with your tail, and it will explode, allowing you to escape

Two marines will join the marine who lured you in. Find a way back up, and kill them. I recommend waiting for them to disperse, because taking them on as a group IS suicide and a guaranteed way to end up being blasted to pieces. These guys are annoyingly alert and can spot you even if you're technically out of their line of sight. You need to make sure you are completely obscured from their vision.

They will also try and take cover by the two sentry turrets. However, they are still lure-able, so simply hiss at them, and they'll saunter back over as if nothing happened. Head back to the power generator in the top-right corner, and take out the power breaker indicated. From there, you will now have to head to the bottom-left, and you will find a second power generator. Be aware that there is an active sentry turret in front of the main building.

Once the power is out, you will then have to enter the third outbuilding. Fortunately, the upper floor is now accessible. Enter through the second floor, and headbutt open the door to the lower floor by pressing and holding cn_X. You will find the eighth royal jelly container on the floor. Break open the next door, and kill the marine inside.

Once on the lower level, enter the vent in the floor. If you turn around, you will find the ninth royal jelly container. Turn back around, and follow the vent all the way to the end, and take the right turn. Continue following the vent, and exit the vent. Turn to your left, and enter the vent right in front of you. Turn around, and you will find the tenth and final royal jelly container of the level. Exit the vent, and deal with the two marines.

Now, the third marine may or may not come down the stairs. This is not the hard part, even though they have a smartgun. The hard part is harvesting the final civilian. He will be upstairs, but he will arm a grenade and kill himself if you get too close. You will need to pounce on him from afar, and then finish him off whilst he is stunned. Harvest him, and then destroy the computer.

Three more marines will arrive outside and enter the building through the ground floor. They will slowly head their way upstairs. They should enter one at time, giving you enough time to take them all out. If they enter as a group, then you will have to wait for them to leave. You can either deal with them, or head straight for the exit. Alternatively, you could just rush down before they enter and use the vents to escape without having to deal with them.

The exit will be the large metal door on the right immediately as you exit the building and around the corner on the right. Head through the door. This is the end of the fourth mission for the alien campaign.

Level Five: Ruins

Under Pressure

Solve the riddle of the Ruins

Under Pressure
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Grim Reaper

Harvest all available civilians in the Alien Campaign

Grim Reaper
3 guidesOffline Game ModeSingle PlayerCollectable

Alien vs Predator

Create a new species

Alien vs Predator
1 guideOffline Game ModeSingle PlayerMain Storyline

This is the toughest level of the alien campaign, due to it containing the only boss fight for the alien campaign. You must fight: not one predator, not two predators, but THREE predators. Two youngbloods and an elite. There are also seven harvestable civilians, one of which being a particularly tricky one. Anyway, you will start the level on top of a building in the corner of a set of ruins.

There will be five harvestable civilians outside, at least one, but sometimes two of which will wander around, whereas two should be locked in a room you have to gain access to. There will also be a number of roaming combat androids, so specific locations simply cannot be given. Anyway, so immediately after you begin, a combat android will appear below you. Quickly kill it, and return to the bottom of the stairs. Facing the stairs, turn left, and climb down to the area below.

Continue forward up the stairs, and climb up the wall in front of you. You should see the first royal jelly container tucked in the corner there. If you then climb up the wall over the building and drop down into the path below on the ground, you should find the second royal jelly container in the corner. From here, return back to the start of the level. You will need to head to the building in the corner directly opposite from you.

At the bottom of the stairs (facing away from the stairs this time), turn left, and follow the walkway around the corner to the right. Continue all the way until you reach a building. Continue forward, and you should see a destroyed section of wall with a set of stairs leading down. The third royal jelly container will be next to the stairs on the right.

From here, you will want to head to the platform in the centre of the map and use the vent in the middle of it. The problem is that there will be a civilian examining the vent who will run off over an edge and kill himself, thus voiding the Grim Reaper achievement if you kill the combat androids he is with. The workaround is to spook the civilian by letting him see you, following him, and harvesting him before he runs off of the edge. You will also need to wait until you are out of range of the combat androids for obvious reasons.

Once the civilian is harvested and any combat androids have been taken out, go down the vent in the centre of the central platform, go down the tube, and exit the vent at the bottom. You will land on a pressure plate, which you need to activate to progress with the level. Depending on which way you are facing, the fourth royal jelly container will be either to the left or right.

On one side, you will see a combat android and civilian standing outside. The container is on the other side, literally as soon as you round the corner. Instead of continuing outside, it will be along the wall to the side. Continue to the other side to take out the android(s), and harvest the civilian. There is a pressure plate in the middle which you need to stand on as part of a mission objective.

From here, climb up to the right side (facing away from where you entered the area), and there should be some stairs leading into a building. Once inside, do not go up the stairs to the top level of the ruins. Continue around, and you will find the fifth royal jelly container. Go back down to the pressure plate, go through the area underneath the central platform to the other side, and activate the pressure plate there.

This should remove barriers blocking a series of drainage ditches and net you the 'Under Pressure' achievement. Continue back to the pressure plate on the other side, and access the vent on the left. The sixth royal jelly container will be here. These are all of the royal jelly containers in this area. Take out the remaining combat, and harvest the remaining civilian(s). If you haven't missed any, you will bag the 'Grim Reaper' achievement.

Once all loose ends have been mopped up, head back to this specific drainage ditch vent. You can use it to access the room with the two last civilians in it, completing a mission objective in the process. Anyway, once the two civilians are harvested, you will be tasked with destroying the humans' power source. There will be some stairs leading to the second level where you will find a power generator. You can take it offline by destroying the power node in front of it by pressing and holding cn_X.

This will open the doors to the locked room, but this will also spawn a combat android. Exit the door on the second level, kill the android, and continue through the door up the stairs ahead to continue to the next area. As you enter the next area, the seventh royal jelly container will up on the pyramid to your left. Climb up it, and it will be in front of a predator statue. Bear in mind that the two youngbloods will be taking potshots at you with their plasma casters.

They can't one-shot you, but it will hurt if one hits you. Just be sure to take cover if you see them shooting at you. Continue back to the area you started, but stop at the bottom of the stairs. The eighth royal jelly container should be to the left, next to the stairs. If you turn around and continue all the way opposite, the ninth royal jelly container will be behind the building. The tenth and final royal jelly container of the level, and the last one of the entire campaign will be inside the combat arena. Go to the big metal door at the back of the arena, and the container will be on the left, up the stairs by the door.

Once all collectibles are acquired, it is time to enter the arena, and kill the two youngbloods. Bear in mind, either one can wreck your shit at close range. You will be joined by your siblings, but try not to rely on them too much. They can run good interferences, and be wonderful distractions, however. This should go without saying, but DON'T even THINK about taking them on when they are together. It will also be much easier once one of them is down.

Anyway, you will have to rely on good old fashioned hit-and-run tactics. Once they are dead, the Elite predator will arrive. He is an even bigger pain in the arse. Unlike the predator you fought in the marine campaign, he has just the one health bar. With this guy, you need to be even more careful if that is possible. Fortunately, however, you can see how much health he has left. When he is weak enough, you will need to harvest him.

This predator can kill you in mere seconds, so don't stick around. Rush in, land a good hit, and then run away. Even if you miss, just leg it, because you can go from super-OP alien, slayer of men and predators, to the predator's bitch in literally three seconds. A different strategy is to simply take potshots at him whilst wall-climbing. Once his health is low enough, you will need to harvest him. Once you do so, you will net the 'Alien vs Predator' achievement. This is the end of the sixth and final mission of the alien campaign, as well as the end of the alien campaign as a whole.

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