As the cutscenes end, you will find yourself crash-landing at the Cerberus base. The soldiers will have prepared for your attack, and a massive battle will ensue in the hangar. This area is a wide open battlefield, with docking equipment and crates providing much of the cover. Protection is sparse in the middle of the area, making maneuverability better but cover worse. The decision of which path to take is up to you.
If you do go towards the center, you will have better chances against the Atlas mech but also better chances of being flanked by the enemy ground troops. If you choose to go with this tactic, run towards the center of the area and use your Biotics (as well as those of your party) to weaken or kill as many of the footsoldiers as you can as they scramble to find cover. Take cover by one of the boxes yourself, as the Atlas mech charges you. Command your squad to focus their full power on the mech, ideally from positions in cover from opposite sides of the battlefield. That way, when your squad-mates begin shooting the mech from the sides, it may be distracted and expose its back to you. Hit it from behind when you can, and be sure to keep some kind of cover between yourself and the Atlas mech’s large guns when it does turn towards you.
As you do this, watch out for the remaining soldiers who you couldn’t quite get when the attack began. A few Centurions are likely to be alive still. You will want to have a powerful Shotgun or some sort of close range Biotic or Tech power, like Tech Armor or at the very least a charged melee attack, at the ready just in case you bump into one of these enemies as you scurry around the crates for cover.
The second approach is also the more tactful and safe, but it won’t kill the enemies off as quickly. Take cover to the right, behind the table and crates. From here, shoot out at the Cerberus footsoldiers and move slowly down the room against the right wall. Leave your squad behind on the right side as you curve around the walls to reach the left side. From here, you can focus your fire from both sides of the room into the killzone in the middle of the room. Focus on taking down the less imposing footsoldiers first, so that it is less likely they will be able to flank around you while you take down the mech. When all of the regular soldiers are dead, order your squad to attack the Atlas mech with everything they’ve got.
After the battle, Cerberus will attempt to vent all of the air out of the hangar. You will have to sprint to the control console at the other end before the timer runs out. Run to the ladder to the left and climb it to reach the control room. Use the Hangar Bay Compression Controls and EDI will begin to hack into it. She will stop the venting, but she can’t open any of the other doors, either. A group of Cerberus soldiers will run in to attack you after you stop the air from being sucked out. The wave will be led by a group of Guardians. As they filter in, Assault Troopers will be directly behind them. Hit them with a Grenade, or use Singularity, Nova, or Concussive Shot to take out a group of them. Setting up a Rocket Turret by the entryway that the enemies will be coming through can also be effective if you’re an Engineer, and if you have enough time to construct it. You can even set up a trap using the Scorpion, if that’s you only option. It won’t be as effective as the previously listed options, but it works.
Attack the Guardians when the explosion rocks them, killing them instantly. Alternately, use Pull to yank their shields away and follow it up with a barrage of gunfire. Mow down the enemies behind the Guardians where they stand, using Shockwave to disorient them all if necessary, and get in close to finish the job if you have to. If you use your Biotics effectively, you should be able to take down these enemies before they even have the chance to make it through the doorway.
Head down the hall here and turn to the right to reach the next area. You will have to face down yet another team of Cerberus soldiers, made up of multiple Centurions and one Nemesis. If you can catch them all together again, you will be able to use a similar strategy as you did last time, taking out multiple enemies using Biotics like Singularity and Shockwave, or Tech like Grenade. Just be sure that you kill the Nemesis before it can establish a sniping position, as you won’t want to be on the other end of that attack. When the battle is over, take a right to reach the Rotation Controls.
Before you activate the console, turn around and search the wall to find Med Kits in a Medical Station. Activate the Rotation Controls, spinning the landing pad platform and aiming a ship directly at the doors that you need to breach. Head to the left and walk through the doors here. Next to the ladder, search to the left to find a PDA. Then head down the latter. Hit the switch on the shining console at the base of the ladder to send the ship crashing through the doors below, opening up a new path for you to take.
An Atlas mech will emerge and fire upon you, while two regular soldiers will sprint to opposite sides of the room, where unmanned Atlas mechs await them. Pull out a Sniper Rifle and stop those soldiers from reaching their mechs. If you don’t, you’ll have three Atlas mechs to fight at the same time. If you successfully stop them, commandeer their mechs for yourself. If not, cower behind cover and order your squad to kill the mechs one at a time. Use cover efficiently and spread your squad out as a distraction, and it will be possible, if not easy. When the battle is over, you will be free to run deeper into the facility.
