After not playing the game since release, I decided to try to do a run where I got 100% of the achievements on the first run without an NG+. I’ve compiled some of my tips for how to accomplish this for anyone who might be interested. However, it’s technically not possible because of at least one achievement in ME3.
Guide to Insanity Mode
I played an adept for all three games. Biotics are too powerful to skip out on.
ME1 is actually incredibly easy in the LE. Equip the best sniper rifle you can find. Upgrade singularity completely.
A slight cheese for difficult encounters (massive geth or thresher maws): If you back up far enough (100 meters or so), enemies will stop firing, and you will no longer be “in combat”. This will res your teammates. They will remain dead almost the whole game, even with constant babysitting and telling them where to stand.
From 100 m away, you can still snipe anything. Singularity isn’t reliable from that far away, though. Enemies do not recharge health.
Ignore the tentacles that come out of the ground and “exit combat”. The tentacles will recede once you leave the area, and you can come back to just fire as much mako as you possibly can into the TM itself. You can always jump the Mako in order to avoid the spit attack.
Garrus and Tali. Equip Garrus with a sniper rifle and upgrade that skill. He can help with shields and he is effective from far away. If you’re too far out of combat, though, he won’t help. Ensure that Tali is using her pistol and not her shotgun (or any other weapon). As an adept with a strong singularity, crowd control is cake. Anything that rushes at you (like husks) are not a threat at all. Part of my reasoning for G/T is that they’re my favorite characters and they have the best dialogue throughout the game, but Tali was stronger than I expected her to be on insanity. You can also fully upgrade the First Aid skill on Garrus, and Decryption/Electronics on Tali.
Make sure you are constantly “pausing” to direct your squadmates and unleashing powers. Powers are on individual cooldowns, not universal, which is very helpful.
Using all the squadmates. However, if you run around the Citadel doing errands, that counts. You can rack up your Ashley points this way. I recommend Ashley/Wrex in the Citadel because he calls her out on her racism during elevator chats. Actually, Wrex has the best elevator chats with everyone.
You must choose among Liara, Ashley, and Kaidan (but A/K are straight), and you cannot sacrifice your love interest on Virmire. Pretty straightforward. Pro-tip: don’t romance Liara if you’re going for a 100% achievement playthrough unless you’re a bad person who wants to break her heart.
ME2 is…an “insanity” step up from ME1 in terms of difficulty. It took me a long time to find strategies that worked for me, because even though I’m writing a guide, I refused to look up videos or anything of the like for my own run and figured out all the strats myself.
Cover is your absolute best friend.
So is Garrus (again). Recruit him early. His loyalty mission is probably one of the hardest missions if it’s the first thing you do, because you have only useless weapons and weak powers. However, you have warp, and you have Miranda (who also has warp). And you have singularity. Power spam, keep running out of pistol ammo, and make sure you are micromanaging Miranda. I left Zaeed with Garrus, and took Miranda around with me. I also used the AOE arc heavy weapon. After acquiring him, upgrade Garrus for weapon damage as much as you can–don’t go for squad ammo.
After getting Garrus, get Mordin. His incinerate can be upgraded to be far better than warp for armor. Your goto squad is now Garrus and Mordin. Jacob should be left on the Normandy to rot, because he’s useless, irritating, and his father is about as garbage as he is.
Next: get Kasumi’s loyalty mission done. The Locust is a huge improvement over the trash weapons you have at this point. Carnifex (from Mordin) is very good but has no ammo. Because it’s just you and Kasumi for this mission, it’s easier than other missions, so even a Predator is just fine. If you’re having trouble keeping her alive during this mission, she can aggro-drop with Shadow Strike to get her to safety–however, that means all aggro will be on Shepard.
Mission order does not matter from here on out, in my opinion. You will want to do a ton of exploration (get the probe upgrade!) so that you can get all the ship upgrades. Plus, if you have a lot of extra materials at the end of 2, they get upgraded into war assets in 3–which shouldn’t matter if you 100% 3, but higher EMS is always better.
Unpopular opinion that hurt my soul: pick Morinth over Samara. She will give you dominate as your bonus power, which makes collector missions much easier. One thing to remember is that the more enemies are shooting at other things, the less they are shooting at you. Aggro dropping is an absolute must, which is why Infiltrator is so popular with Insanity runs.
After I got Tali, I replaced Mordin with Tali to have G/T again. Personal bias, yes, but there are a lot of mech enemies in 2, so Tali is great for that. (That being said, Mordin and Garrus were my suicide mission team. I would take Mordin instead of Tali if I was facing mostly organics, and Tali if a lot of synth enemies.)
Don’t be afraid to use Unity. There’s a lot of medi-gel everywhere. Micromanaging your teammates is important, but they’ll die anyway, guaranteed.
I went with sniper rifle as my bonus weapon, unsurprisingly. Garrus and I sit in the back again, while Mordin…uses incinerate and dies a lot.
If you don’t care about the saving your squad achievement, throw Jacob in the vent. He volunteered for it, anyway. And that way you don’t ever need to hear from him again. If you do care, send Tali. She has dialogue in 3 about the vent. Other than that, I recommend a different guide for how to survive the suicide mission, because that can become a spiderweb diagram. I will recommend, though, that you send Kasumi back to the Normandy with the survivors.
I mentioned Mordin/Garrus for the suicide mission–but that’s the first half, where you need to deal with a lot of armor. For the second half, I took Thane instead of Mordin (and that might have been the only time I used him), because he is good at barriers. If you want to be adventurous, switch Garrus with Miranda so that you have extreme barrier control.
Many of the original ME2 achievements were a bit difficult (like surviving onslaughts of enemies without a squad). However, because those don’t matter, you should have no issue being able to get every achievement with this setup.
You have to be a scumbag if you’re doing a 100% playthrough, and you must cheat on your ME1 love interest. If you picked Liara in ME1, you can “reaffirm” with her in Lair of the Shadow Broker, but that does NOT grant you Paramour. Kelly Chambers also does not “count”. The good news is, Garrus and Tali are now options. Thane is the cutest romance, but he also dies in 3, so you can always go Kaidan/Thane/Kaidan if you’re a female Shepard. Or Kaidan/Thane/Traynor. Possibilities are endless.
Pro-tip: There’s a booty-call button in your cabin after the suicide mission. You can always have cuddle time with Garrus or Tali.
Fun fact: Legion is a god-tier gamer.
It’s even easier than ME1! The only issue is that, if you play as an adept, you cannot get all the achievements in a single run. You cannot upgrade a weapon to level 10, and you cannot get the pyro achievement (unless you have Ashley alive and loyal, and use her squad power, but Kaidan isn’t racist, so it’s a no-brainer for me to leave her on Virmire).
However, at the beginning of the game, with Anderson teaching you the ropes, you can be an Engineer with Incinerate. Anderson will keep asking you if you forgot how to shoot, but there are husks that keep crawling out if you don’t pull out your gun, and you can get all your incinerate kills right there for the pyro achievement.
For upgrading to Level 10 weapon, unfortunately, you do need to start an NG+, and the first time you can do it is after talking to the Council (after Mars, you have to go to the Citadel, and cannot enter the Normandy until after speaking to them). This is a complete waste of time, but completionists gotta…complete. It’s even more salt in the wound because you cannot change classes for NG+, so you cannot knock out the pyro achievement at the same time as your weapon upgrade achievement.
You get Garrus early! It’s great! His AP ammo can be upgraded to do more weapon damage. His final skillset (Turian Rebel) can be upgraded to give extra weapon damage, and he has an outfit for weapon damage. I highly recommend the “Garrus ascends to godhood” video for maximum Garrus impact. You are now a Garrus medi-gel dispenser who sometimes uses singularity. Save up enough money for the N7 Typhoon and you will never need to kill a banshee again because that man will do it for you within seconds. Yet another reason there is no Shepard without Vakarian.
This game, I had no reason to use a sniper rifle. It’s too heavy, so just carry your friend the Carnifex with an ammo upgrade and have fast biotic cooldowns. The best gun in the game for Shepard, imo, is the Cerberus Harrier. As soon as I could afford it, I bought that and that was the only gun I used (poor Carnifex). The only con is that is has no ammo, but ammo crates are everywhere, and enemies also drop ammo.
You should never have to turn down the difficulty from Insanity if you have your squad set up well. In general, you want to make sure you are set up for constant biotic/tech explosions. If you have ammo powers in your squadmates, upgrade them for damage, not squad ammo. Again, upgrade your biotics for combo damage (Warp/Double Throw wrecks face). Put one point into Pull so that you can take down Guardians quickly. You cannot stay in one place too long, because multiple enemy types are too dangerous up-close (Geth Hunter, Geth Pyro, Banshee, Brute, etc). Ensure you’re comfortable with combat rolling from cover to cover, especially because a single grenade will kill you on Insanity. Also, if you’re in cover and an enemy crosses your path, you can always grab them from cover and insta-kill them, even if they are shielded.
Omega DLC should be your first. Leviathan gives you dominate, yes, but dominate seemed less powerful to me in this game than in ME2. That’s just my opinion, though. In addition to spending time with my girl Aria in the Omega DLC, you get Flare. With a fast cooldown, flare can be used to make incredibly powerful biotic combos. Warp/Flare is amazing. However, it should be noted that Lash is better at pulling enemies out of cover than Pull, and it also takes Guardian shields. Because Aria is such a strong squadmate, you can easily do this DLC without being very high-levelled.
Even though Citadel DLC is the true ending of the game, I recommend doing it early (pre-original ending for sure). You will get the best armor in the game through the Armax arena (if you get above 9999 points). You can also farm infinite money fairly easily, because each gold medal nets you a solid amount of credits. If you have a 10% citadel discount from the intel terminal, you are all set to buy everything in the game (if you care, but really, other than buying the Typhoon, Harrier, model ships, and fish, what do you need to spend money on?).
I struggled with this a bit. EDI was my top choice because of incinerate, but if you can tolerate James, he’s your “krogan replacement” squadmate and can also be upgraded to go into weapon damage. Hand him a Typhoon and he will do good damage. However, he’s James, which is problematic. Unfortunately, Tali is no longer a solid squadmate–there are not enough synthetic enemies, and her abilities are just not as strong as other squadmates. Plus, she’s pistol/shotgun. Javik is also a very good choice, because Dark Channel is excellent for biotic combos, lasts a long time, and travels from enemy to enemy. You can also hand Javik a Typhoon, though he is not very effective with it. Kaidan is a surprisingly decent choice, because he can help with combos, shields, and can keep himself alive with a barrier (plus, can carry a Typhoon!).
The game is plenty easy at this point. With Garrus and your biotics, your second squadmate is just dialogue icing, really, which is why you can be flexible with it. There’s only two hard fights in the main storyline, which are the final two fights. The very last time you fight with your squadmates, infinite Banshees and Marauders spawn. If you kill a Banshee, another will take her place. I think there are three on the battlefield at a time, but I was running for my life, so I might be wrong on that. There are rocket launchers around the battlefield, but ignore them. It’s not worth it. This is where you play chicken. There’s a covered room in the left top of the map (facing the Reaper). You can hide in there with your squadmates, combat rolling to avoid Banshees. Do not attack them. Your squad will, of course, be melting them, but the second they drop one, another will appear. There’s absolutely no reason to have more healthy Banshees than necessary. Once you can activate the Mako (it’s not really a Mako, but I’m calling it a Mako), make a mad dash run. Ignore the Marauders. Ignore everything. Run for your life for the 10 feet or so it takes to get to the car, and even if you’re at less than one bar of health, as soon as you interact, you are safe in cutscene land. Then comes the Final Boss, Marauder Shields. This man laughs in my face as I attempt to headshot him while mostly dead. I have no advice other than…good luck aiming?
Wrex/Garrus was the best choice for the Citadel DLC in terms of doing damage (Wrex can keep himself alive incredibly well with his little packs, and they refresh whenever you pick up grenades). However, for Mirror Match, Wrex is a bad choice. Very bad choice. His AI is broken, as is Grunt’s. Miranda should be good in theory, but she was dead the entire time. You can easily get a 15k score on MM in the arena with a few modifiers (which will give you the Phantom armor!). Kaidan, of all squadmates, was my second squadmate, because of his barrier and shield abilities. Micromanage your squad so that they are out of the line of fire. All three of you should be focusing one clone at a time. Vanguards and Infiltrators will force you to leave cover occasionally, which means you need to be combat rolling constantly. If you get meleed, you are most likely dead, because stun-lock can kill you easily in MM–especially with modifiers.
More about the Armax Arena
For super elite collectors, you also want to be combat rolling constantly. Singularity is NOT effective in the arena, unfortunately, because too many things are armored/shielded/barrier-ed (again, much more so with modifiers). Wrex and Garrus will wipe the floor with collector super elite easily, except that Wrex will be dead every time he headbutts a Praetorian (and honestly, I kind of admire him for his dedication to kroganhood). Reaper super elite is laughably easy with this team, also. Note that the arena is MUCH easier than the rest of the game, in general, because the difficulty is capped at Normal (so Hardcore and Insanity are actually both the exact same as Normal–which means you can face-tank! Grenades aren’t insta-death!). New enemies are also introduced in the arena, such as the Geth Bomber and the Dragoon. Neither of them are problematic, especially because they’re both armored opponents, but it’s good to know that the factions aren’t exactly the same as during the “normal” game.
You have the chance to reaffirm with anyone as soon as you pick them up. Each one of the squadmates has a “date” (or friendship hangout), during which you can lock-in. If you’re romancing Garrus, it’s during the shooting competition, and you’d better let him win, you monster. Once you lock in, you cannot change, and Paramour is unlocked as soon as you make that choice. Unlike ME2, you cannot be an incessant flirt during this game. Note that Thane does not count. You can reaffirm with him at the hospital, and have some really uncomfortable dialogue (…can’t the rest of the hospital hear you…?), but that does not grant you the achievement. Also, even if you broke up with Liara during Lair of the Shadow Broker, you have to re-break up with her (or reaffirm with her, even if you did that in ME2) regardless, because LoSB wasn’t part of the base ME2 game (which meant that your “decision” with her didn’t exist for a lot of players).
Easy Storyline Mistakes
Choose the Renegade option when you meet Kelly Chambers again so that she changes her identity. This will ensure her survival through the Citadel attack. Also, choose the Renegade option with Javik at the end to ensure his survival (otherwise he commits suicide after the Reapers are beaten).
My personal opinion on the ending
You can either pick the Illusive Man archetype, the Saren archetype, or the Anderson archetype. For me, this is a pretty simple choice. Yes, EDI dies. Yes, the Geth/Quarian alliance is meaningless now. However, you’ve been trying to kill the Reapers for three whole games now. It makes no sense for you to change your mind at the ending. Additionally, no matter your opinion on the last 15 min of the game, the writing of ME3 is phenomenal. It’s easily my favorite game of the three, because the stakes are so high, the characters are so good, and I genuinely feel like the Normandy is my home.