First off, what a ride that was! I played it through on normal having imported my ME1 character, wasnt satisfied so decided to dive right in. First up my stats: 
 
Soldier , imported at 30 
chose the widow sniper rifle 
toyed with reave for a while, eventually settled for warp ammo 
 
Amazing experience, not like the call of duty or bad company games difficulty level, where it feels cheap and youre just hopping from save to save, insanity made it so the tactical side to combat was far more important than just hittin em up 
 
Grunt got a lot of use, found him as an overall gun platform as invaluable, and on levels where there are tons of them ghoul things coming at you his charge attack (melee) one hits them.  some seriously intense gameplay was coaxed out of me, the disabled collector ship was damn near impossible but it just felt so satisfying to finish it. By the time i had got all/most the upgrades the slack was let up (slightly!!) and i found myself having to reload very rarely. 
 
Also i banged miranda 
hell yesssssssssssssss 
 
i also managed to haul everyones sorry asses outta the collector base 
found it easier than when i did it on normal

First off, what a ride that was! I played it through on normal having imported my ME1 character, wasnt satisfied so decided to dive right in. First up my stats: 
 
Soldier , imported at 30 
chose the widow sniper rifle 
toyed with reave for a while, eventually settled for warp ammo 
 
Amazing experience, not like the call of duty or bad company games difficulty level, where it feels cheap and youre just hopping from save to save, insanity made it so the tactical side to combat was far more important than just hittin em up 
 
Grunt got a lot of use, found him as an overall gun platform as invaluable, and on levels where there are tons of them ghoul things coming at you his charge attack (melee) one hits them.  some seriously intense gameplay was coaxed out of me, the disabled collector ship was damn near impossible but it just felt so satisfying to finish it. By the time i had got all/most the upgrades the slack was let up (slightly!!) and i found myself having to reload very rarely. 
 
Also i banged miranda 
hell yesssssssssssssss 
 
i also managed to haul everyones sorry asses outta the collector base 
found it easier than when i did it on normal

My hat is off to you. I finished the game then decided to start again on insanity. I'm probably about halfway through the story, but I just can't seem to get past the part I'm suck at. I've been trying for like six months. 

at times it was very very very frustrating, and starting at level 30 ish (may have been a tad lower) certainly alleviated that alot 
gonna say the widow was my best friend, that with heightened adrenaline rush and upgrades had me one shotting most enemies 
a tip i picked up on 
towards the end of the game most fights are on platforms 
samara or whoever with heavy lift just lobs people off, its recharge is neglibgible you can do some serious damage

i started a new career as an infiltrator and the invisibility power, when combined with a sniper rifle, really helped me out of some sticky situations. also, using the Arc Projector really helps when taking on multiple enemies.  

Good work! I know that when I played it I didn't do a lot of the loyalty missions, and ended up with three or four deaths. I did think that the Praetorians were a little cheap, but I also went with the geth shield boost instead of warp ammo, so that may be why.  
 
@sixdemonbag : You know, it is possible to do both Tali's and Legion's missions and have both of them still like you, you just need either your renegade or paragon meters to be high enough to persuade both of them.

not like the call of duty or bad company games difficulty level, where it feels cheap and youre just hopping from save to save, insanity made it so the tactical side to combat was far more important than just hittin em up 
 

I used Mordin and Miranda on my insanity playthrough. AOE incinerate dealt with husks like they were no problem because after their armor was gone, throw one shotted them (I was an Adept). Having Miranda's warp was also a good thing to have on top of my own. Insanity was a lot of fun, as it provided a sense of urgency that wasn't there on other difficulty settings.I played through the game on insanity first and then I did hardcore my second time through and it really didn't feel like there was ever much of a problem running through the levels. The enemies would drop almost instantly and it removed the sense of urgency from all of the combat.

" @hicks91 said:

not like the call of duty or bad company games difficulty level, where it feels cheap and youre just hopping from save to save, insanity made it so the tactical side to combat was far more important than just hittin em up 
 

I didn't mind Insanity on ME2 but c'mon, that's a bullshit statement. ME2 relied on a flawed mechanic that the MW1 Devs admitted was a problem and took out of MW2 - infinite spawns until you cross an invisible line.   There's only a few sections where this comes up but goddamn it all if it wasn't a huge pain in the ass. The one that sticks out is going after Harkin in the warehouse (with the flame canisters on the ceiling and Mech at the back of the room) - unless you cross the line to activate the Mech the Blue Suns just keep pouring in and there's noting tactical or challenging about it, it's just cheap. That being said, congratulations on beating it on Insanity. "

" I used Mordin and Miranda on my insanity playthrough. AOE incinerate dealt with husks like they were no problem because after their armor was gone, throw one shotted them (I was an Adept). Having Miranda's warp was also a good thing to have on top of my own. Insanity was a lot of fun, as it provided a sense of urgency that wasn't there on other difficulty settings.I played through the game on insanity first and then I did hardcore my second time through and it really didn't feel like there was ever much of a problem running through the levels. The enemies would drop almost instantly and it removed the sense of urgency from all of the combat. "

Congrats! I personally beat it with a sentinel for the extra shields. I totally agree that the game is completely different on Insanity. Not until Insanity do you realize how important squad tactics, ammo skills, proper weapon selection and power use are. Most of my playthrough was with Miranda (for her squad buff) and Garrus (because he's awesome). But I would usually swap out Garrus for Mordin on husk heavy levels since, as mentioned before, his incinerate owns a lot and in most husk levels if you manage to kill them with incinerate before they get to melee range his low health isn't an issue :)

Congratulations to you, sir. I played as a level 30 Soldier for awhile on Insanity but could not seem to get past a certain area. I will try again! But I most likely will fail. So good job to you; go buy some cookies.

Good work dude, Insanity is no Joke. I tried importing at level 30 and it was too crazy. Restarted with a level 1 and it was a little easier. Enjoy that S-Rank!

i just played the game and i got most of the achievements that way 
except the zaeed one i farmed that, that mission was just fucked up

I heartily congratulate anyone who can complete that game on insanity. After only a short time trying to replay the game on that difficulty I realised it was going to be way beyond my ability.

I've been slowly chipping away at this on insanity for a few months now with a lv 30 vanguard and it has to be the single most difficult game i've ever played. The worst bit so far was at freedom's progress where you start off overwhelmed by husks coming from everywhere until you take out the two weird biotic versions. I just couldn't get past it until I realised the exploit that you could send in your squad without triggering the husks to then take out the two fuckers without reprieve.
now each mission is started with a significant amount of dread for the inevitable wall I'll encounter. Grunt's loyalty mission may be left for last...

I'm about to play on Insanity, what's so hard about it? Enemies just do more damage and have more health? Because I think I could handle that with max upgrades. I finished the game on Hard only dying a couple times (due to headrushing into 5 enemies at once).

you can drop the scions in four shots with the widow sniper rifle and adrenaline rush 
just run and gun at that bit, your homies will take care of the husks 
but yeah freedoms progress was p tricky

 @TheBalticOne:yeah it's the tank husks that are dicks. complete bullet sponges. i found praetoris easier; just a case of taking potshots and running around cover 
 
@Geno: i thought the same thing. the trouble is everything becomes much harder to kill you become so much easier overwhelmed. plus the AI gets so accurate it could shoot an apple off mars. so weapon choice, squad and ammo types become paramount. go into a mission with the wrong mix and an already hard game becomes insanely difficult.
 
since my last post i've booted up the game again and gone straight into the abandoned collector ship.
jeeping fuck
i just get destroyed as soon as the collectors show up. any tips?

"

I'm about to play on Insanity, what's so hard about it? Enemies just do more damage and have more health? Because I think I could handle that with max upgrades. I finished the game on Hard only dying a couple times (due to headrushing into 5 enemies at once).

"

Hearing you guys all talk about it makes me want to give Insanity a shot. I'd kinda convinced myself I wasn't going to enjoy it at that difficulty, but ... well, you're all making it sound doable.

Congrats 
I played on insanity for my first run through the game and chose vanguard. The game wasn't too difficult, and I can only remember one instance where I died constantly for an entire night. Surprisingly, I woke up the next day and beat it on my first try. The difficulty drops significantly on insanity once you teach Shepard Barrier.

I'm at the Collector Ship as an imported level 30 Adept. I don't know hoe many times I've tried now, it's damned near impossible. Just when you're making progress, and start thinking to yourself that you're finally, finally going to make it, you die. I have no idea how I'm supposed to beat it.

Grats on finishing Insanity. I  found Tali and Jack to be the best team. 

" I'm at the Collector Ship as an imported level 30 Adept. I don't know hoe many times I've tried now, it's damned near impossible. Just when you're making progress, and start thinking to yourself that you're finally, finally going to make it, you die. I have no idea how I'm supposed to beat it. "

" @guiseppe said:

" I'm at the Collector Ship as an imported level 30 Adept. I don't know hoe many times I've tried now, it's damned near impossible. Just when you're making progress, and start thinking to yourself that you're finally, finally going to make it, you die. I have no idea how I'm supposed to beat it. "

agreed. I'm starting to think that this is just plain beyond my ability. i use the arc projector to remove the barriers from the first group of collectors so i can throw them off the platform, then harbinger comes along and proceeds to be a grade a piece of shit. by the time i've taken care of him the second platform arrives and i'm usually one party member down after losing both med packs. harbinger then comes again and i get royally F'd in the A. this is without even mentioning the scion hanging around throwing eggs (/shockwaves) at you.  oh mass effect, why must you treat me so bad? "

seeing you guys all had problems gonna say how i did it 
place miranda to the left of the platform, and whoever else you take to the right, samara is quite a good choice heavy reave + heavy warp = bye bye barriers, thought i used grunt for raw power and health 
whenever a harbingers comes, take him out,  if you chose the widow it shouldnt be too bad, just focus fire and bring him down.  
leave the scion, its pesky but overall its not too bad 
try and kill enemies outright, dont whittle them down to low health as theyre the ones harbinger favours 
 
after the first two platforms things ease up, then you just gotta take care of the praetorian :) (hint: the enemies that spawn with him are not infinite)

I will try more later I guess, but I've spent more or less the whole day trying to do that platform business. I've tried different positions, tactics, characters, methods.. I don't know what to do at this point. It seems to all be down to luck really, as I've almost gotten past it a few times. It's such a pain that you can't save that mission for later and go upgrade yoru stuff and gain loyalties.
 
Edit: So I jumped back in, and for some reason everything was easy as hell. It's like enemies did less damage and I did more, hardly any deaths or anything. Almost like the game set itself to easy, but I checked, and it's still on insanity. Maybe I was experiencing some kind of bug before? Or now? The only difference between now and then is that I rebooted the console, but I've done that earlier today too, so I don't understand why it was so unbelievably easy now. At least it got me through the level, finally.

"thanks, in part, to my desire to finish the game with one shot from the m920 Cain. When i finally hit with that, it was amazing. Definitely the most satisfying final shot i have ever fired in a video game. "

What's hard about it is that enemies don't just do more damage and have more health. They are Much smarter. Your teammates on the other hand, are not. You find that out very early in a Very bad way. I just finished the game on insanity myself, internet high-five OP!...Nice!

i found the last boss easy 
once again widow sniper rifle is your friend 
the fact i had 8 x medigel was useful too 
and hard shields, that upgrade is essential

DONE!
thanks everyone for your help. i actually did a little involuntary dance after i got past the first bunch of collectors. then i realised i had a whole level to get through... but i got through that without too much trouble. i'd take a praetorian over a hoard of collectors any day. and heavy charge really helped skip past all the husks at the end (those little fuckers).

That new arc projector makes killing ghouls so much easier on insanity.