Mass Effect 2

From http://www.xbox360achievements.org/forum/showthread.php?t=30...

Survive all five waves in the battle for Object Rho.

This one is missable, because you can get knocked down but won't actually die, and the story will go on. So if you don't want the achievement, just let yourself get iced immediately. But we aren't here for that, are we ?

You have to survive 5 waves of attackers, so if you get downed, immediately DASHBOARD OUT.

Luckily, I found an exploit to win the fight easily. At the start of the fight, do not stay there but go to the right, up the little stairs and take cover behind the side of the console here. You should be behind the console's left side if you look at it, and have some glass cover on the left, then the stairs. Now you will hardly ever be attacked from the left, and all attacks towards you will finish in your little console wall. And the best part is ? You can shoot THROUGH it, without getting out of cover. The same goes for the left side of the room according to Baihu1983 and some classes find hiding behind the "L" shaped console better for the YMIR fight because the Mech doesn't rush you there, so try both !

For those who want to play fair, beware of grenades that will knock you out of cover, and here are my tips :

Wave 1 : regular Soldiers with regular weapons. Just go hide in the corner I previously talked about. Even if there is a passage on your left, the enemy will hardly ever take it unless you come out of cover for an ammo run (they will hide behind the 2 columns instead), making it the best cover in the room. Same goes for the left side of this symmetrical room.
Wave 2 : regular Soldiers with 2 Heavy's with Flamethrowers. Theses guys can rape you, so again, use "my" cover and you will be safe. You can even detonate one guy's tank when the other is next to him and take the 2 down in 1 shot on Casual.
Wave 3 : regular Soldiers with 1 Heavy Vanguard and 1 Heavy Flamethrower. The first is a pushover and won't rush you, so eat away his armor, and ice him. Be careful with the Flamethrower Heavy because he WILL rush you.
Wave 4 : regular Soldiers with 1 Heavy Engineer and 1 Heavy Flamethrower. The first is a pushover and won't rush you, so eat away his shields, and ice him. Be careful with the Flamethrower Heavy because he WILL rush you.
Wave 5 : same, plus an YMIR Mech. Yeah. In close quarters. Yeah... If you're playing a maxed-out Infiltrator like me that can do 1000 points of damage in one shot, go into Tactical Cloak and headshot the Mech twice with your Widow and it will go nuclear, so move your ass out of cover after that ! If you're playing another class, use Power Armor or Heavy Geth Shield Boost with a combo of Heavy Overload, Heavy Incinerate and/or Heavy Warp, the best biotic power in the game. Try to use Warp Ammo as well, again the best ammo in the game. And use your best weapon, of course, depending on your class. Too bad the frag grenades from Mass Effect 1 aren't there anymore.

Author: Asturgis

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You have to survive 5 waves of attackers, to survive the waves just go to the left of the room when you start and go in the corner behind an L shaped desk. They wont even come near you.

BEST SPOT TO TAKE COVER: Immediately to your left at the start, behind an L-shaped white desk.

Said desk is in the top left of this picture:

If you stay in cover behind this position, your only problems should be enemies with flamethrowers and the YMIR Mech.

Dashboarding is NOT ENTIRELY NECESSARY. If the screen starts to go red/black - meaning you have been downed - immediately press start, then load the second autosave. You get one right before going into this room and the cutscene.

I used a maxed out Sentinel, and though any class should work, Power Armor, Cloak and Adrenaline Rush for Sentinels, Infiltrators and Soldiers respectively will help if you run a bit low on ammo (as well as surviving longer). Lower the difficulty if needed.

When you see a Pyro, kill him immediately. Remember you can save a little ammo by shooting the tank on his back, and damage any nearby enemies in the ensuing explosion.

If you start to run low on ammo, hopefully you've killed some enemies to your left beforehand. Activate Armor, Cloak or Adrenaline, then run on the left side of those pillars in front of you. They will offer a little bit of protection from enemy fire.

When the Mech comes, focus all your attention on him. While he will get almost as close as the Pyros who rush you, he never came around the front of that desk, and I was still safe. WHEN HE DIES, Sentinels need to have Armor activated, and anyone else needs to be as far away as you can without severely compromising yourself. Back up to the wall behind you and the explosion shouldn't kill you.
SENTINELS: DO NOT use Throw when the Mech's protection is gone. Both times I did, he went down for a few seconds but then glitched and was standing on the desk I you should be using for cover. If you got his protection down when he's farther away, more power to you.

I got this on Hardcore (because after beating Insanity, even Veteran feels a little too easy), and it shouldn't be too hard on the lower difficulties, especially Casual. Good luck.

**If there are any problems/suggestions for this solution, please leave a comment so I can modify it. Thanks!**

I did this without using any "exploits". I was a level 30 soldier with the following weapons:
-Mattock Heavy Rifle
-Carnifex Hand Cannon
-Geth Plasma Shotgun
-Widow Sniper Rifle
-Collector Particle Beam.

I also had the "Squad Warp Ammo" ability, activated throughout most of the battle, and played this on Casual difficulty (it doesn't matter for the achievement, but I assume this strategy would work for all difficulties.)

When you start the fight, take out the guys flanking you on your right (if you're facing the Reaper Artifact). There should be a pillar directly to your right, sort of in a corner. If you take cover behind this pillar so that you are facing the artifact, the door you came in is on your left, and the door the enemies are coming from is across the room to the right you shouldn't have an issue with enemies flanking from the right.

I used the Mattock with Warp ammo on all of the soldiers, trying for headshots and using my Impact shot as much as possible. Target the Pyros first, as sometimes they do come from the right, and once you get hit by one flamethrower your pretty much done for.

There will be an increasing amount of Elite soldiers that have a shield, and they don't provide much of a problem. A few shots to the head will take them down. You will know you are on the last wave when someone radios: "send in the heavy mechs". Now, there is only ONE heavy mech and for me it went around the Artifact and came at me from my left.

I had run out of ammo at this point for the Mattock and used the pistol to take out the Elites that were surrounding it. I then switched to the Particle Beam and let loose on the mech. The pillar provided enough cover so that it's rockets couldn't do much damage. They still made me stumble but because of the mech's position relative to mine behind the pillar, it couldn't damage me very much at all.

Once I got the mech down to the health I used an impact shot and followed up with a shot from the Particle Beam. When the mech dies, it sets off a large explosion, much larger than killing a mech anywhere else in ME2. This instantly kills any enemy that is within about 5-10 feet of it. At this point, there should be 2 or less enemies in the room. For me, the last enemy was an Elite hiding between the pillar and the wall to the left of the door the enemies were coming through.

After everything in the room is dead, the Artifact will explode/EMP and you will be knocked unconscious. The achievement should pop as the screen goes to dark red/black.

I dont know about you guys but I had not played the game for so long that I got to this point with the worst weapons and my character was not set up for using powers. I found this achievement extremely frustrating and time consuming until I found what I like to call the Jesus Pillar (thanks Left 4 Dead).

When you start out just kill the guy on your right real quick (he is all alone) then behind you are the doors you came through and to your left and back a little ways (if your looking at the back of your head from where you started out) there is a pillar next to stairs leading to a desk with terminals.

I found the desk really hard with no bionic powers because too many enemies have the drop on you so it takes forever to whittle them down when every time you pop up you have four or five guys dropping your shields and putting your health in the red. If you hide behind the pillar at the bottom of the stairs though you will have no difficulties completing this (stick to the pillar and not the wall)

When hiding behind the pillar I took my time and I only had to come out once to get ammo. All your enemy will stay to the left of the room and you will be plenty protected from them so pop out when you can and take them down one at a time. It seemed to me that when I killed the special enemy (the ones with the better shields and weapons) it triggered the next wave so instead I killed the minions first and when I had just one or two enemies left I would run from the pillar to get ammo.

Note: when using the pillar the enemies will cluster in two areas, upstairs to your left which you will be protected from and in front of you on the other side of the pillar. So your ammo will pile up in two areas making it easy to reload quickly and run back to the pillar.

Things to watch out for are the flame thrower dudes so make sure you ALWAYS have some shotgun ammo or they will ruin your day. I tried dropping them as soon as they came out the door because I think there is only like two of them. One in wave 2 and wave 4 but I cant remember.

Another side note is that on the final wave the mech will come out and if you were like me and had awful weapons and powers then start shooting at him as soon as he comes through the door. He never would come past the pillar for me so it was no problem taking care of him but the concern was that if he was too close when he dropped then you will die from the concussion blast so just drop him quickly and then hug the pillar and you should be fine.

Please comment if this helped you, thanks!

A bit of extra info - this DLC doesn't trigger until you've completed the Horizon mission. This means you need to recruit the first four 'core' squad members (Grunt, Modin, Garrus and Jack), this causes the Horizon mission to trigger and once that is completed you should get a message on your private terminal.

I mention this because I did a run-through on Insanity and didn't realise I'd missed this achievement. Starting on the easy setting, skipping through the dialogue and running through everything quickly it took me 2 hours and 36 minutes to arrive at this point - about another 5 after that to trigger the stealth achievement and another 10 or so to survive 5 waves (took me a couple of tries even on easy.. but as others have said on the far left of the room is a L shaped table, just get behind that and pull out your sniper, then your pistol and finally your combat rifle).