The Insane Difficulty is locked when first starting to play this game. In order to unlock this mode you must beat the game on once before or join a co-op game (the host only needs to have Insane unlocked).
You must beat every act and chapter in Insane mode to unlock this achievement. You are allowed to play the chapters in any mode: co-op, single player, or a mixture of both. The achievement will unlock as long as you have credit for beating each chapter in Insane mode. The bolded text is a great plan of attack by HolyHa1fDead:
The easiest way to do this is using a mixture of both solo and coop.
In solo you are instantly killed and have to restart from the last checkpoint, but in coop you are downed and your partner can either revive you or keep going on their own until that wave of enemies are killed and you are automatically revived. It's like having 1 extra life. However when you split up it is like solo and if either of you are downed you have to restart from the last checkpoint, so there is no advantage to doing those bits coop, you are better off doing them solo.
Dom isn't going to win the game for you, but he is better than an idle controller, unless you want to use the second controller as your extra life.
The best way to play coop is system link in the same room, then split screen and lastly over the Internet or system link between different rooms, because even with Mic's it is good to know where you both are and be able to see what each other can see.
Another advantage of coop is that instead of trying to decide to drop the long shot for the torque bow or shotgun, you can carry one and your partner can carry the other
This achievement is stackable, so unlocking this achievement will unlock the "Soldier" achievement as well as the "Mercenary" achievement if you don't have it already.
The whole story takes around 5-7 hours to beat.
If you are having issues beating this mode by yourself I would HIGHLY recommend playing with a real person other then AI. It will make your progression through the game much easier.
Here is the -BASIC/SHORT WALK-THROUGHS- in each ACT. If you would like MORE detail please see my solutions on each act:================
ASHES -ACT ONE-
CHAPTER ONE - 14 YEARS AFTER E-DAY - Easy, this is a training mission. Just stay back and use the hammer burst or lancer.
CHAPTER TWO - TRAIL BY FIRE - You should have no major issues in the first half (outside). I would get chainsawed allot so I recommend staying back and using longer range weapons such as the hammer burst or lancer. In the second part of this chapter (once you enter inside the building) you may run into some issues so I recommend carrying at least one grenade to plug up the hole.
CHAPTER THREE - FISH IN A BARREL - This chapter is fairly easy IF you do it correctly. The first challenge is killing the locus on the gunner turret. If you go on the right side and use the short tunnel to get to him it will make things much easier. DON'T USE GRENADES YET. The second part is where you will be inside a small area with four emergence holes. You will do MUCH better if you plug ALL four holes.
CHAPTER FOUR - FORK IN THE ROAD - The first part of this chapter is okay. I personally choose to take the left path so I would not have to deal with the gunner. The second part in this level was a major pain. I would recommend going to the right side to take out the gunner and other enemies from a far (I used hammer burst but lancer works great too). Make sure you plug up the hole that comes up after you clear the enemies out of this room (it appears in the back where you entered).
CHAPTER FIVE - KNOCK KNOCK - I stayed back and shot with my hammer burst and lancer during the whole chapter. Used my chainsaw in smaller areas.
CHAPTER SIX - HAMMER - This area is pretty straight forward. Stay back even after you get the Hammer of Dawn I stilled used my hammer burst. Even though your mostly inside the rooms are fairly large which allows you to stay back.
CHAPTER SEVEN - WRATH - The level is pretty straight forward. Stay back and use the hammer burst or lancer. You will mostly be inside with plenty of cover and if they start getting close you can chainsaw/shotgun them.
CHAPTER EIGHT - CHINA SHOP - The level is pretty much the same in all difficulties. You shoot the berserker so he follows you, jump out of the way so he destroys the doors and once your outside hit him good with 4 Hammer of Dawns.
IF YOU WANT MORE DETAIL OR TO WATCH VIDEOS FOR ACT ONE PLEASE SEE THIS SOLUTION:
DESPERATION -ACT 5-
CHAPTER ONE - Special Delivery - Pretty straight forward and quick chapter. Take cover (there is PLENTY OF IT) and use longer range weapons (hammer burst or lancer) to take out enemies on ledges and on the ground. View the video below (first one) to see it in action.
CHAPTER 2 - Train Wreck - In this chapter they allow you to stay back and take cover. Watch out for the Theron Guards since they can do major damage if you get stuck. During the Berserker fight you’re going to have to get her in the back of the train. Once in the back of the train blow up the tank to obtain total victory. Make sure you grab a bow to take down the Reavers. Once inside for the first time you’re going to need to be VERY careful. Take cover on the right side and watch out for Reaver on the outside from both ends. Once you climb up to the top of the train and your outside you will be attacked by several waves of Reavers so hop on the gunner.
CHAPTER 3 - Pale Horse - This is it... big fight here! You will want to use the cover right in front of you (the light will protect you from the Kryll). Use your bow to get the Kryll away from RAMM and then switch to your longshot/lancer and blast him away. Once the Kryll come back switch back to the bow. If you can and get a good shot toss a 'nade into the mix. Once he starts getting close launch a 'nade at him and then run to the other side. You're more than likely going to have to run to the other side if you're playing solo. If you're playing co-op is it easy to kill him before he gets to you (one using the longshot and the other using the bow). Watch the fourth/last video on help to kill him during solo play.
IF YOU WANT MORE DETAIL OR TO WATCH VIDEOS FOR ACT FIVE PLEASE SEE THIS SOLUTION:
- Become good at active reloading. This makes the Locust drop so much quicker.
- Take more cover. Not only do you heal but the Locust do not.
- Work as a team (if your playing with a person) and try to aid your AI partner (he will help some but there are issues with him getting killed allot).
- RAAM can be killed if you have one player with the torque bow (or grenades) to blow away the kryll and then the other player use sniper head shots (active reloads). It will take around 9-13 active headshots to kill him on Insane. If you are still having trouble please see the "A Dish Best Served Cold" achievement for more tips and a video.
I hope that helps!