Welcome to our Aliens: Colonial Marines walkthrough! Below you’ll find instructions on how to complete all 11 missions of the game.
The locations of a few items (dog tags, audio logs, and legendary weapons) are disclosed, though mostly we’ll be pointing you to much needed health packs and armor pick ups.
Perhaps most importantly, you’ll find big tips on how to come out victorious in boss encounters. Oh, and as a quick fyi, this walkthrough was completed on the Soldier difficulty level.
Mission 1 - Distress
After the cut-scene of Hicks making a distress call, you’ll spawn with a Pulse Rifle.
Walk ahead and open the sliding door.
Once across the umbilical cord, just wait a bit for the Inner Door to open.
You can hit LB for your Motion Tracker, which details your objectives.
In the room with downed Marines, wait around for O’Neal to open the gate.
You’re in the room where Ripley fought the Alien Queen at the end of Aliens! Move across to Airway 3D (it’s lit up) and hit the button.
Move along and open the doors. Use your Motion Tracker when the screen prompts you to.
Take a right at the dead end room and torch the door.
Move down the stairs and take a left to get to the survivor, Keyes.
Cut him down. As you do so, you’ll be interrupted by a Xeno. Go through the QTE and then wander around to kill it.
Follow him until you reach the fight with a good half dozen Xenos. Take them out as you move left and up the stairs. Grab the flight recorder as Keyes seals the door.
Follow Keyes out and immediately look left for three supplies on the ground.
Kill the Xenos in the circular room before moving onward to the hallway. Don’t stick around here, just get across the threshold and it will shut.
Pick up supplies as Keyes messes with a keypad. This is before he says (“On the dropship!”).
Once in the main bay again, help the two marines fight off the Xeno waves as Keyes opens up the next door.
After the cut-scene where Keyes gets his chest busted open, jump into the opening O’Neal makes.
In the room with quarantine wrap on the walls, pick up supplies.
Once you get to the giant yellow turbine room, hug the wall to the left as you fight off Xenos.
Once out of the turbine room, grab the ammo and take a right.
You’ll fight against your first Lurker. Just keep your distance and strafe to get a good line of sight. After you’ve killed it, grab the audio log (it looks like a laptop).
Move along until you get back to the turbine room. Take out the xenos as you hug the wall on the right.
Upon leaving the turbine room for the second time, you’ll enter a small network of rooms where a legendary weapon is hiding. It’s a shotgun, useful for the next challenge of covering for O’Neal as he opens the door with the “3” on it.
You’ll find yourself at the first cargo bay. Follow O’Neal to the right and up the stairs.
Once atop the stairs, hug the wall left and use the Pulse Rifle since this is a big open space. Soon O’Neal asks for cover at the next door (shotgun time).
It won’t be long before he gets it open. Follow him through and hit the button in the control room.
As the cut-scene chatter rolls, run to the back of the room to grab some dog tags.
Mission 2 - Battle for Sulaco
You’ll fight humans (Weyland-Yutani soldiers) next.
Move across the room on the left wing, since O’Neal takes the right. Pick up armor from fallen enemies.
Follow O’Neal down the stairs. Before opening the door marked Cargo Rail, explore that very room for plenty of supplies.
In the room where O’Neal complains about being blocked off, jump into the power loader and use it on the huge white door on the opposite side of the room.
Next you’ll come across your first Facehugger! Cute. Mash the QTE to get it off and immediately find your bearings to put a bullet in it.
In this infested room, move across to the right and torch the door.
Keep your flashlight on as you move through this infested area. Consult your Motion Tracker to find Bella and use the Pulse Rifle on Facehuggers.
Say hello to Bella (who has been latched onto by a Facehugger. Hmm... wonder what will happen to her).
Torch the door.
You’ll get to a big dark room, where you can find some dog tags before torching a second door.
Move along this huge hallway with the view to space on the left. Duck behind hardware to avoid fire. Eventually you’ll come across a more armored guy (we’ll call them heavy gunners from now on). Just focus fire. It might not seem like he’s taking damage, but he is.
After you’ve cleared the engineering room of foes, use your Motion Tracker to regroup with your squadmates. Hop in the elevator and close the door again.
More Weyland-Yutani soldiers are ahead. Mow through them until you get to a golden-hued room. There’s a health pack here.
In the next room (still golden-hued) is a tough battle. Be sure to take down the Weyland-Yutani soldiers that are in the central room above, behind glass. Use your underslung grenade launcher if in a tight spot.
You’ll get to an open room where Bella and O’Neal are shooting across to the enemy ship, Don’t bother. Just hit the button on the right.
Move into the hallway, but watch the explosive barrels!
Follow your teammates through the red-hued hallways. You’ll face a heavy gunner here before reaching an elevator. Get in and close the door.
You’ll immediately face a Weyland-Yutani soldier upon exiting the elevator. Kill him and keep going until you reach the next door. Beyond it is another heavy gunner. Pile on the bullets!
Next is an auto-turret. Flank it as your squadmates suggest and power it down with the touch of a button (no bar-filling process here. It’s easy).
On the way to the bridge is another tough battle. Take your time and creep up to the turret before rushing it to power it down.
Mission 3 - Sulaco Falls
Follow your squadmates as the ship begins to fail. In the hallways past the main room, explore the options to your left for a full armor pick up.
Open the door and step into the air stream. Shoot the thing blocking the door on your right and the stream will cease. Then follow your squadmates.
After the view of the burning ship outside, you’ll get to two doors straddling a corner and prompted to pull out your Motion Tracker. Open the door on the right for the flamethrower, then proceed through the door on the left.
Defeat the Weyland-Yutani soldiers here and move on.
Get in the elevator and hit the button.
Take two immediate lefts out of the elevator for supplies.
Follow your squadmates and cut the door open.
You’ll find Weyland-Yutani soldiers fighting xenos here. Try to keep your fire even between the two sides. If you fall to the watered floor, just find your way back to the open yellow/white elevator in the corner.
Follow your squadmates out and through a few more enemies before getting to the room with a keyboard button to hit!
You’ll get to a cargo bay with steam valves going crazy and four or five Xenos. Use your flamethrower, then follow O’Neal to the underground opening.
Follow your squadmates to the golden-hued room, where Xenos will rush you. Don’t worry about friendly fire! There isn’t any.
Keep following your squadmates till you get the big room at the end of the space-view halls. Hit the elevator button and you’ll find a big battle between Marines and mercenaries.
Kill the mercenaries on the ground floor before moving up to hit one of the two keyboards.
Before hitting the second, you’ll have to move to the control room in the back to activate the crane. Then it will take a good minute to make the second keyboard accessible.
Jump down to the ground floor and run to the ship.
Mission 4 - No Hope in Hadley’s
Congrats, you’re on a planet! Just move along until you get to the structure and open the door.
Once inside, follow your squadmates to the door and torch it.
After the pep talk at the map, follow O’Neal. He’ll bash the door you need in through.
Keep your Motion Tracker out as you find the five sensor points. You can sprint with it out!
Replace one of the sensors when prompted and prepare yourself for a bunch of Xenos.
Make your way back to the main room only to be sent back again for the turret. Grab it, though not when Xenos are around. You can’t shoot or sprint with this thing in hand.
Deploy it in the main room. After this battle, your superior will tell you to grab the smart gun. That’s not the turret! It’s a gun in the big old case.
Follow O’Neal to an underground smart gun set piece. Mind your maximum ammo here, because there are a lot of Xenos. Use bursts, and don’t shoot unless you know you have a lock on a Xeno. Eventually you’ll get to a room where you’ll have to clear a few Lurkers before the gate opens.
Before torching the next door, grab Gorman’s pistol on the left and the full armor pick up on the right.
Mission 5 - The Raven
In this mission you’ve got no weapons or Motion Tracker, but you still have the welder.
Take two lefts from where you free yourself from the nasty infested wall, then open the grate on the floor.
Follow the sewer and look out for flashing blue button pads. Hit those and keep still when the husks are around. If they’re not facing you, you can usually sneak in a few steps or more.
You’ll eventually get to a big red door. Torch it and enter. Move along the grate and jump across to get to the next switch.
Jump down and torch the next door.
Run down the pipe to the left and you’ll get to a room with three inactive husks. The best way to get past them is to crouch and walk.
You’ll get to the part where O’Neal advises you to seal every door behind you. Do so or you’ll lose!
Take the elevator up to find O’Neal and, yes, your guns!
Step out to regroup with Bella and find Reid. The Pulse Rifle is best for these big open spaces. Be sure to grab supplies on the side of the main path throughout this sequence.
Eventually you and O’Neal will be tasked with holding off Xenos while the two ladies work on electronics.
Follow the path after you meet the big Xeno and torch the door.
Eventually you’ll be outside again, looking for O’Neal. When you get to the big Xeno (Bell says “‘Holy [bleep]!”), take a right and crawl under the pipes.
You’ll fight a half dozen Xenos before moving through the shipping container. Drop down and pick the right path to survive. The big Xeno appears, take the path that’s 45 degrees to your left and kill the Xenos there.
Go through another shipping container, drop down, and take an immediate left. Jump into the power loader.
You’ll have to box the big Xeno! This isn’t that simple, though if you can work it into a corner you can get a series of punches in. Don’t swing too early, or you’ll miss and it’ll damage you with a head-butt. After dealing enough damage you’ll go through two animations in which you’re choking the Xeno. The third animation kills it.
Learn more: Read all of our Aliens: Colonial Marines articles here.