I'm finally ready to start this game. So, any advice?
Wow, I envy you. You get to embark on one of the best PS3 games you can play .
I recommend doing two playthroughs. The first on Normal difficulty. Use Soldier class and familiarize yourself with the specific-kill-type trophies so you can get just about everything out of the way before your second playthrough. Do your 2nd playthrough on Insanity difficulty. Some people will tell you to use the NG+ option, but I recommend starting fresh. The reasoning here (thanks Lord Maim) is that the game scales to your character's level. So if you start NG+ at a high level, the enemies will be brutal right from the start. However, even on insanity, if you start at level 0, the enemies are not too tough until later in the story.
Make your Insanity run kind-of a speed-run. Don't spend time recruiting or earning the trust of squad-mates who you're just going to sacrifice in the ending sequence anyway.
Also, in between playthroughs, you can start an NG+ on Normal (or even Casual) to max out your character level (I think 30 is the max). This gets another trophy out of your way.
I recommend going through on Insanity on the initial run. It's not that hard, and saves you from having to do a second run through. The enemies scale to your level throughout the game, so it isn't a game in which you need to grind to defeat an enemy, as much as you need to understand the mechanics. I did my entire run as a Sentinel, and felt that being the "tank" and using the squad commands to direct your allies to do most of the killing, why you draw the fire worked out best.
I'm the type of person who thinks you should almost always play the game on the hardest difficulty, if difficulty trophies are required, on the initial run so that you adjusts better to what to expect. If you go at it easy or weak, the game is seriously way too easy and it takes away a lot of the fun of the game's mechanics that you almost have to utilize to beat it on Insanity.
This game isn't terribly hard at any point, and is quite enjoyable to get the vast majority of trophies, which come with doing proper side-quests. Just enjoy yourself.
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I would recommend you to do 2 playthroughs as well. 1st playthrough, start on normal difficulty and have fun with the game, you're gonna wanna do all of the trophies on this playthrough (you could do all the trophies on NG+ and forget about trophies and just enjoy the game. Either way is up to you). Choose whatever class you like the most, and think will give you the most enjoyment. Complete all the loyalty missions, and get the No One Left Behind trophy. The No One Left Behind trophy is pretty complicated, so you might wanna use the trophy guide to make sure you get it.
And once you've completed your first playthrough, you're gonna wanna start the Insanity run. For Insanity make sure you do NOT start a new game+, as it makes Insanity a lot harder as it makes your enemies much tougher and scaled to your level. And as AntoniosBandana said, treat this playthrough as a speed-run, so forget about loyalty missions, and only complete the main missions, as it will shorten down the length of this playthrough. I would say the best class for Insanity is Sentinel, it's got pretty much everything for Insanity. Plus that Tech Armour will save your life. Btw, a tip for Insanity is if you have throw, use throw on a husk and it's an instant kill once you've got it's armour depleted, really helpful on the Collector Ship and Reaper IFF mission.
Anyway, the main thing is, just enjoy the game. It's too good of a game to worry about insanity or trophies. Also, buy this game new so you can get Cerberus Pack which gives you pretty much most of the DLC. Anyway, good luck.
Playthough on normal soilder class (you a thank me later) and pick armor-pierceing rounds then after u beat the game do it one more time on the hardest setting with that same character by the end of this playthough u should have every trophy and have a maxed out sheperd
Get the anti-mater sniper rifle that with maxed adrenaline is a 1 hit kill and be sure to use the matdock assault rifle with the armor piercing rounds you a kill everything in your path with armor piercing rounds maxed and pick tungsten rounds with those 2 guns And adrenaline Rush u can't lose
I played once through insanity and as a Vanguard. People say that's suicide, but in all honesty I didn't have much trouble apart from the first few missions (due to lack of powers and upgrades). If anything, I found it OP later on and battles could literally last seconds. Sentinel and Soldier are also solid classes.
ME2 isn't a straight up shooter and it does require a little strategy in stripping enemies of their protection. Once you get familiar with the fighting sequences, you'll wish you started on a harder difficulty. Remember, you can hold R2 or L2 to pause the action around you, check your surroundings and issue more calculated commands to your squadmates, or look for flanking opportunities, or just find a nice place to get cover.